1
|
Risk factors, outcomes, and complications associated with combined ventral hernia and enterocutaneous fistula single-staged abdominal wall reconstruction. Hernia 2021; 25:1537-1548. [PMID: 33538927 DOI: 10.1007/s10029-021-02371-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/22/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE To compare two cohorts of patients; those with isolated ventral hernias (VH) and those with VH and enterocutaneous fistulas (ECF). Risk factors for surgical complications (including recurrent ECF) and outcomes during single-stage VH with ECF surgical reconstruction were analyzed. METHODS A retrospective review was performed from 2008 to 2019. We compared two cohorts of patients with single-stage VH repairs: (1) ventral hernia repair alone (hernia alone), and (2) combined VH repair and ECF repair (hernia plus ECF). Inclusion criteria were patients ≥ 18 years of age with pre-operative VH either with or without an ECF, who underwent open hernia repair and ECF repair in a single-stage operation, with a minimum follow-up of 12 months. Patient risk factors, operative characteristics, outcomes and surgical-site complications were compared using univariate and multivariate analyses. RESULTS We included 442 patients (hernia alone = 401; hernia plus ECF = 41) with a median follow-up of 22 months (12-96). Hernia plus ECF patients were more likely to have inflammatory bowel disease (IBD)(OR 4.4, 95% CI 1.1-17.5, p = 0.037), a history of abdominal wound infections (OR 3.4, 95% CI 1.5-7.9, p = 0.004), reoperations (OR 4.9, 95% CI 1.6-15.4, p = 0.006), superficial soft tissue infections (OR 2.5, 95% CI 1.1-6.1, p = 0.044) and hematomas (OR 8.4, 95% CI 1.2-58.8, p = 0.031), compared to hernia alone patients. ECF recurrence was associated with diabetes mellitus (DM) (n = 8, 73% vs. n = 6, 20%; p = 0.003) and surgical-site complications (n = 10, 91% vs. n = 16, 53%; p = 0.048), compared to ECF resolution. CONCLUSION Risk factors for developing ECF were IBD and history of abdominal wound infections. Single-staged combined ECF reconstruction was associated with reoperations, soft tissue infections and hematomas. DM and surgical-site complications were associated with ECF recurrence.
Collapse
|
2
|
Managing adolescent pregnancy: The unique roles and challenges of private general practitioners in Malaysia. MALAYSIAN FAMILY PHYSICIAN : THE OFFICIAL JOURNAL OF THE ACADEMY OF FAMILY PHYSICIANS OF MALAYSIA 2019; 14:37-45. [PMID: 32175039 PMCID: PMC7067509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
INTRODUCTION Managing adolescent pregnancy in the primary care setting is complex, as it requires doctors to navigate through a combination of medical, social, financial and legal needs. Objective: This study explores the perspectives of private general practitioners on their roles and challenges in managing adolescent pregnancy in Malaysia. METHODS Nineteen private general practitioners in Selangor and Kuala Lumpur participated in in-depth interviews in 2015. A topic guide was used for interview navigation. Participants were asked to discuss their experiences and approaches in managing pregnant adolescents. We used purposive sampling to recruit consenting private general practitioners who had experience in managing adolescent pregnancy. The verbatim transcripts of the audio-recorded interviews were analyzed using thematic analysis. Data reached saturation at the nineteenth in-depth interview. Results: Two themes emerged. Under the theme 'inadvertent advocator,' participants described their tasks with regards to building trust, calming angry parents and delivering comprehensive counseling and care related to the sexual and reproductive health of adolescents, including requests for abortions. Theme two, 'challenges of private general practitioners,' refers mainly to personal and religious conflicts arising from a request for an abortion and deficiencies in support and multidisciplinary integration within their practice settings. CONCLUSION General practitioners practicing in the private sector identify themselves as active players in supporting pregnant adolescents but face many challenges arising from the personal, religious, professional and community levels. Addressing these challenges is important for optimal care delivery to pregnant adolescents in this community.
Collapse
|
3
|
Knowledge, utilization and barriers to primary care services for sexual and reproductive health among adolescents in secondary schools in Selangor, Malaysia. MALAYSIAN FAMILY PHYSICIAN : THE OFFICIAL JOURNAL OF THE ACADEMY OF FAMILY PHYSICIANS OF MALAYSIA 2019; 14:10-17. [PMID: 31289626 PMCID: PMC6612277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Early sexual debut, partner violence, pregnancy and sexually transmitted infections contribute to negative health outcomes among adolescents. While the primary care clinics offer accessible sexual and reproductive health (SRH) services to adolescents, it is uncertain whether adolescents are aware of and utilize these services. This study aimed to examine Malaysian adolescents' knowledge, utilization and barriers to primary care services for SRH. A cross-sectional survey was conducted from August to November 2011 among adolescent from five randomly selected schools in Selangor, Malaysia. A self-administered questionnaire was used to assess their knowledge, attitudes, sexual behaviors and utilization of SRH services. A total of 680 adolescents participated in the study. One in ten of the adolescents were aware of the availability of SRH services, and only 6.9% of them had ever visited a primary care clinic for SRH. About 75% of them felt uncomfortable going to a primary care clinic for SRH services. Knowledge and utilization of primary care clinics for SRH among adolescents in Malaysia is poor.
Collapse
|
4
|
Preoperative prediction of Difficult Laryngeal Exposure (DLE) during Microlaryngoscopy (ML): Use of LARYNGOSCORE in a scottish teaching hospital. Int J Surg 2018. [DOI: 10.1016/j.ijsu.2018.05.262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
5
|
The Gent-O’Clock: Improving patient safety - gentamicin monitoring in an acute receiving surgical ward. Int J Surg 2018. [DOI: 10.1016/j.ijsu.2018.05.167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
6
|
Loop-mediated isothermal amplification (LAMP): a versatile technique for detection of micro-organisms. J Appl Microbiol 2018; 124:626-643. [PMID: 29165905 PMCID: PMC7167136 DOI: 10.1111/jam.13647] [Citation(s) in RCA: 326] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 11/09/2017] [Accepted: 11/13/2017] [Indexed: 12/11/2022]
Abstract
Loop‐mediated isothermal amplification (LAMP) amplifies DNA with high specificity, efficiency and rapidity under isothermal conditions by using a DNA polymerase with high displacement strand activity and a set of specifically designed primers to amplify targeted DNA strands. Following its first discovery by Notomi et al. (2000Nucleic Acids Res 28: E63), LAMP was further developed over the years which involved the combination of this technique with other molecular approaches, such as reverse transcription and multiplex amplification for the detection of infectious diseases caused by micro‐organisms in humans, livestock and plants. In this review, available types of LAMP techniques will be discussed together with their applications in detection of various micro‐organisms. Up to date, there are varieties of LAMP detection methods available including colorimetric and fluorescent detection, real‐time monitoring using turbidity metre and detection using lateral flow device which will also be highlighted in this review. Apart from that, commercialization of LAMP technique had also been reported such as lyophilized form of LAMP reagents kit and LAMP primer sets for detection of pathogenic micro‐organisms. On top of that, advantages and limitations of this molecular detection method are also described together with its future potential as a diagnostic method for infectious disease.
Collapse
|
7
|
Metabolic cost during tyre and rope functional training. JOURNAL OF FUNDAMENTAL AND APPLIED SCIENCES 2018. [DOI: 10.4314/jfas.v9i6s.77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
8
|
Exploring the current and future role of the pharmacists in osteoporosis screening and management in Malaysia. Int J Clin Pharm 2018; 40:450-457. [PMID: 29380234 DOI: 10.1007/s11096-018-0597-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 01/19/2018] [Indexed: 10/18/2022]
Abstract
Background Several studies have found that pharmacists can assist in screening and prevention of osteoporosis by referring patients for bone mineral density scans and counselling on lifestyle changes. In Malaysia, screening osteoporosis in all elderly women is not mandatory due to its cost. One approach to address this gap is to develop a pharmacist-led osteoporosis screening and prevention program. However, there is a paucity of data on the perspectives of Malaysian pharmacists in this area. Objective To explore the perspective of stakeholders (policy makers, doctors, pharmacists, nurses and patients) towards the role of pharmacists in osteoporosis screening and management. Setting A primary care clinic located within a teaching hospital in Kuala Lumpur, Malaysia. Method Patients (n = 20), nurses (n = 10), pharmacists (n = 11), doctors (n = 10) and policy makers (n = 5) were individually interviewed using a semi-structured topic guide. Purposive sampling was used. Interviews were transcribed verbatim and analysed using thematic analysis. Main outcome measure Perspective of stakeholders on the current and future role of pharmacists. Results All participants perceived pharmacists to be suppliers of medication, although there was some recognition of roles in providing medication advice. Nonetheless, these stakeholders were eager for pharmacists to expand their non-dispensing roles towards counselling, creating awareness and screening of osteoporosis. Interviewed pharmacists referred to their current role as 'robotic dispensers' and unanimously agreed to spread out to osteoporosis management role. Conclusion Under stakeholders there is a willingness to expand the role of pharmacists in Malaysia to non-dispensing roles, particularly in osteoporosis screening and management.
Collapse
|
9
|
The synthetic molecules YK51 and YK73 attenuate replication of dengue virus serotype 2. Trop Biomed 2017; 34:270-283. [PMID: 33593007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Dengue virus infection has been posing alarming economic and social burden on affected nations. It is estimated that 50-100 million dengue infections occur annually with over 2.5 billion people at risk for endemic transmission. In the effort to develop effective antiviral agents, we previously reported potential antiviral activities from selected array of natural products and compounds against dengue virus serotype 2 (DV2). In this study, we report the synthesis of two efficacious novel compounds, YK51 and YK73, and their activities against DV2 replication. Both compounds were chemically synthesised from nicotinic acid using a modified method for the synthesis of dihydropyridine. The products were tested with cell-based assays against DV2 followed by a serine protease assay. As a result, both YK51 and YK73 exhibited intriguing antiviral properties with EC50 of 3.2 and 2.4 µM, respectively. In addition, YK51 and YK73 were found to attenuate the synthesis of intracellular viral RNA and protect the switching of non-classic mechanism of protein translation. These compounds demonstrated inhibitory properties toward the activity of DV2 serine protease in a dose dependent manner. These findings demonstrate that both YK51 and YK73 serve as DV2 serine protease inhibitors that abrogate viral RNA synthesis and translation. Further investigation on these compounds to corroborate its therapeutic properties towards dengue is warranted.
Collapse
|
10
|
An analysis of inter-professional collaboration in osteoporosis screening at a primary care level using the D'Amour model. Res Social Adm Pharm 2016; 13:1142-1150. [PMID: 27780658 DOI: 10.1016/j.sapharm.2016.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVES This study describes the perspective of patients, nurses, pharmacists, doctors and policy makers to identify the level of collaboration and the areas for improvement to achieve inter-professional collaboration between doctors, nurses, pharmacists and policy makers in a primary care clinic. METHODS Patients (n = 20), Nurses (n = 10), pharmacists (n = 11), doctors (n = 10) and policy makers (n = 5) from a primary care were individually interviewed using a semi-structured topic guide. Purposive sampling was used. Interviews were transcribed verbatim and analysed using thematic analysis informed by constant comparison. RESULTS Patients, doctors, nurses, pharmacists and policy makers were eager for pharmacists to be more proactive in creating health awareness and conducting osteoporosis screening at the primary care clinic via inter-professional collaboration. These findings were further examined using the D'Amour's structural model of collaboration which encompasses four main themes: shared goals and visions, internalization, formalization and governance. This model supports our data which highlights a lack of understanding of the pharmacists' role among the doctors, nurses, policy makers and pharmacists themselves. There is also a lack of governance and formalization, that fosters consensus, leadership, protocol and information exchange. Nonetheless, the stakeholders trust that pharmacists have sufficient knowledge to contribute to the screening of osteoporosis. Our primary care clinic can be described as developing towards an inter-professional collaboration in managing osteoporosis but is still in its early stages. CONCLUSIONS Inter-professional collaboration in osteoporosis management at the primary care level is beginning to be practised. Efforts extending to awareness and acceptance towards the pharmacists' role will be crucial for a successful change.
Collapse
|
11
|
[Anxiety disorders in type 1 neurofibromatosis: A case report]. Arch Pediatr 2015; 22:956-60. [PMID: 26228808 DOI: 10.1016/j.arcped.2015.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 01/06/2015] [Accepted: 06/03/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1), also known as Von Recklinghausen disease, is one of the most frequent human genetic diseases, with a prevalence of one case in 3000 births, an autosomal dominant mode of inheritance, and a high rate of new mutations. NF1 has markedly variable clinical expression, with manifestations ranging from mild lesions to several complications and functional impairment. The complications are age-specific. Psychiatric disorders are more frequent in NF1 than in the general population, especially in children. They include dysthymia, depressive mood, anxiety, and personality disorders. Bipolar mood disorders or schizophrenia are rather rare. The majority of studies have focused on physical health and neurocognitive function in NF1, whereas psychiatric disorders associated with this disease remain unclear and poorly documented. This report is based on a clinical case and discusses the relationship between neurofibromatosis type 1 and psychiatric disorders, particularly anxiety disorders. PRESENTATION OF CASE This case concerns a 13-year-old girl, the first child of healthy and non-consanguineous parents. The patient's history showed normal psychomotor and psychoaffective development. Her father and paternal grandmother had isolated café-au-lait spots. In June 2013, a subcutaneous mass appeared in her right thigh. She consulted a neurologist and was explored. The physical examination revealed signs of NF1. She had café-au-lait spots on the trunk and extremities, and a neurofibroma in the right thigh. Bilateral ophthalmic examination revealed multiple Lish nodules. After 1 month, a psychiatric consultation was requested for sad mood and night terrors. Obsessive compulsive disorder and generalized anxiety disorder were diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. CONCLUSIONS The current psychiatric literature does not provide full explanations of anxiety symptoms associated with NF1. Some authors have tried to explain the link between NF1 and psychiatric disorders, and several etiopathogenic hypotheses have been discussed. In our case, a concomitant diagnosis of NF1 and anxiety disorders was made at the age of 13. However, anxiety symptoms started to appear before age 4; they increased gradually and occupied the foreground. This would strengthen the hypothesis of genetic determinism in NF1 patients. The question that arises is: is it a fortuitous association of psychiatric disorders and NF1 or are they psychiatric manifestations induced by a multisystem disease? More detailed investigations are necessary to clarify the etiopathogenic and psychopathological mechanisms that would cause psychiatric comorbidity associated with NF1.
Collapse
|
12
|
Palliative Radiation Therapy to Metastatic Breast and Lung Cancers in the Middle East Region: Five Years’ Experience at a Tertiary Center in Iraq. Int J Radiat Oncol Biol Phys 2014. [DOI: 10.1016/j.ijrobp.2014.05.2042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
13
|
Alteration of cell cytoskeleton and functions of cell recovery of normal human osteoblast cells caused by factors associated with real space flight. THE MALAYSIAN JOURNAL OF PATHOLOGY 2013; 35:153-163. [PMID: 24362479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Experiments involving short-term space flight have shown an adverse effect on the physiology, morphology and functions of cells investigated. The causes for this effect on cells are: microgravity, temperature fluctuations, mechanical stress, hypergravity, nutrient restriction and others. However, the extent to which these adverse effects can be repaired by short-term space flown cells when recultured in conditions of normal gravity remains unclear. Therefore this study aimed to investigate the effect of short-term spaceflight on cytoskeleton distribution and recovery of cell functions of normal human osteoblast cells. The ultrastructure was evaluated using ESEM. Fluorescent staining was done using Hoechst, Mito Tracker CMXRos and Tubulin Tracker Green for cytoskeleton. Gene expression of cell functions was quantified using qPCR. As a result, recovered cells did not show any apoptotic markers when compared with control. Tubulin volume density (p<0.001) was decreased significantly when compared to control, while mitochondria volume density was insignificantly elevated. Gene expression for IL-6 (p<0.05) and sVCAM-1 (p<0.001) was significantly decreased while alkaline phosphatase (p<0.001), osteocalcin and sICAM (p<0.05) were significantly increased in the recovered cells compared to the control ones. The changes in gene and protein expression of collagen 1A, osteonectin, osteoprotegerin and beta-actin, caused by short-term spaceflight, were statistically not significant. These data indicate that short term space flight causes morphological changes in osteoblast cells which are consistent with hypertrophy, reduced cell differentiation and increased release of monocyte attracting proteins. The long-term effect of these changes on bone density and remodeling requires more detailed studies.
Collapse
|
14
|
Real space flight travel is associated with ultrastructural changes, cytoskeletal disruption and premature senescence of HUVEC. THE MALAYSIAN JOURNAL OF PATHOLOGY 2012; 34:103-113. [PMID: 23424772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Microgravity, hypergravity, vibration, ionizing radiation and temperature fluctuations are major factors of outer space flight affecting human organs and tissues. There are several reports on the effect of space flight on different human cell types of mesenchymal origin while information regarding changes to vascular endothelial cells is scarce. Ultrastructural and cytophysiological features of macrovascular endothelial cells in outer space flight and their persistence during subsequent culturing were demonstrated in the present investigation. At the end of the space flight, endothelial cells displayed profound changes indicating cytoskeletal lesions and increased cell membrane permeability. Readapted cells of subsequent passages exhibited persisting cytoskeletal changes, decreased metabolism and cell growth indicating cellular senescence.
Collapse
|
15
|
Unusual presentation of mycosis fungoides as a lump in the scalp. Singapore Med J 2011; 52:e226-e228. [PMID: 22173261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a case of mycosis fungoides in a 27-year-old woman who presented with a lump in the forehead. The condition was confirmed with tissue diagnosis. Gallium scintigraphy accurately delineated the complete extent of the disease, and served as a reference for objective assessment of response of the disease to treatment.
Collapse
|
16
|
|
17
|
A Phase I Clinical Trial of CHT-25 a 131I-Labeled Chimeric Anti-CD25 Antibody Showing Efficacy in Patients with Refractory Lymphoma. Clin Cancer Res 2009; 15:7701-7710. [DOI: 10.1158/1078-0432.ccr-09-1421] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
18
|
The need for ‘Good Clinical Practice’ in health care research. S Afr Fam Pract (2004) 2009. [DOI: 10.1080/20786204.2009.10873848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
19
|
The Effect of Bases and Formulation on the Release of Indomethacin from Suppositories. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639048609042611] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
20
|
Effects of Binders and Moisture Content on the Disintegration, Hardness and Friability of Paracetamol and Orphenadrine Citrate Tablets. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639048909052516] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
21
|
|
22
|
A case of cutaneous larva migrans acquired from soiled toilet floors in urban Kuala Lumpur. THE MEDICAL JOURNAL OF MALAYSIA 2008; 63:331-332. [PMID: 19385496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Despite being a common skin dermatosis in the tropics, physicians in the tropics may miss the diagnosis of cutaneous larva migrans for other pruritic skin manifestation. This is especially in those who live in urban housing with no history of travel. Cutaneous larva migrans, an intensely pruritic skin pathology is mainly contracted by people with history of beach holiday or contact with moist soft sand which had been contaminated with dog or cat faeces. This article reports a patient who presented with intensely itchy papular spots over the dorsum of his foot after walking barefooted in an urban toilet soiled with cat faeces. The patient had initially seen an urban general practitioner who diagnosed the papular skin lesion as an allergic reaction, and prescribed antihistamines. The patient subsequently developed creeping skin lesions and was seen by the author who prescribed albendazole 400 mg twice daily for three days. The patient reported reduction in itching after two days of albendazole treatment and a follow up at ten days revealed a healed infection.
Collapse
|
23
|
Corporate governance and innovative leaders. SOCIAL RESPONSIBILITY JOURNAL 2008. [DOI: 10.1108/17471110810856811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PurposeThe purpose of this paper is to attract readers' attention to the importance of the integration of corporate governance and innovation for companies to strive further in business. The paper also attempts to illustrate how an innovation champion can exist in companies with a good corporate governance structure and fully utilize the structure, at the same time being aware of the limitations of innovation activities. Along the way, corporate social responsibilities should also be taken into consideration.Design/methodology/approachThe objectives of this paper are achieved first through an explanation of how corporate governance structure works and what purpose it serves. By understanding the mechanics of corporate governance, the integration of the structure with other fields of knowledge, in order to boost corporate performance, becomes possible. The paper also makes several references to companies around the world which have integrated successfully.FindingsInnovation is a teamwork effort. Concentrated efforts are needed from every person in the organisation, from the board of directors and all the employees. The main actor in the picture is the board of directors. Also, other critical factors such as culture, conducive environment and rewards very much need to be present in the system.Practical implicationsInnovation, even though deemed risky, must be supported. The board of directors or leaders of corporations must change the way they think. Leaders of corporations must make an effort to understand innovation, and subsequently spread it far and wide among managers by creating corporate policies that support innovation. With a consumer‐centric organizational principle in mind, corporations can improve their innovation success rate. A successful innovation effort requires full participation from everyone in the corporation to ensure that the end results of research and development are for the interests of society at large.Originality/valueCorporate governance is a structure that needs input from other fields of knowledge. Too much faith is put in corporate governance to bring about performance; unfortunately corporate governance is just a structure. There are a lot more factors that should be taken into consideration before achievement can be seen and success stories can be heard. This integration of knowledge is suggested to companies so that they can generate more revenue.
Collapse
|
24
|
|
25
|
Clinical outcome of unicompartmental knee arthroplasty and influence of alignment on prosthesis survival rate. Singapore Med J 2006; 47:796-802. [PMID: 16924362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
INTRODUCTION Various factors that affect the longevity of unicompartmental knee arthroplasty (UKA) include patient activity level, habitus, competence of cruciate ligaments, postoperative alignment, implant positioning and ligament balancing. The purpose of this study was to evaluate the clinical outcome of the open standard UKA and establish the influence of radiological alignment on the survivorship of the prosthesis. METHODS We consecutively reviewed the results of 20 open standard UKAs performed in 17 patients between 1996 and 2000. A single implant type, the Press Fit Condylar Unicompartmental Knee System (DePuy, Leeds, UK), was used in all patients. All patients were evaluated clinically using the Knee Society Rating. Implant positioning and limb alignment were recorded in the standing long leg anteroposterior and lateral radiographs, and various angles were measured. RESULTS The alignment of the prosthesis was found to be good in 19 out of 20 operated knees. One knee with malalignment of prosthesis had to be revised at 23 months follow-up. There was a significant increase in Knee Society Rating of all patients, at a follow-up of 4-8 years. The Kaplan-Meier survival rate using revision to total knee arthroplasty as an endpoint was 91.7 percent. CONCLUSION The long-term outcome of UKA is influenced by positioning and alignment of the prosthesis. With proper patient selection and surgical technique, the outcome of UKA can be definitely improved.
Collapse
|
26
|
|
27
|
|
28
|
A new technique for the determination of contact time distribution (CTD) from tracers experiments in heterogeneous systems. Chem Eng Sci 2005. [DOI: 10.1016/j.ces.2005.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
29
|
A new approach to the joined estimation of the heat generated by a semicontiunuous emulsion polymerization Qr and the overall heat exchange parameter UA. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2004. [DOI: 10.1590/s0104-66322004000200020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
30
|
An Integrated Approach to Polymer Reaction Engineering: A Review of Calorimetry and State Estimation. ACTA ACUST UNITED AC 2000. [DOI: 10.1080/10543414.2000.10744537] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
31
|
Applications of Nonlinear Observers and Control: Improving Productivity and Control of Free Radical Solution Copolymerization. Ind Eng Chem Res 1999. [DOI: 10.1021/ie9806996] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
32
|
Abstract
PURPOSE To determine the value and diagnostic accuracy of planar and SPECT Tc-99m-labeled red blood cell (Tc-99m RBC) scintigraphy in the investigation of suspected hepatic cavernous hemangioma as found on ultrasound. PATIENTS AND METHODS One hundred patients, 89 women (89%) and 11 men (11%), between 22 and 67 years old (mean age, 38 years) were evaluated for liver masses found on abdominal ultrasound. All the patients had previous Tc-99m RBC scintigraphy. The size of the lesions ranged from 1 to 9 cm. The final diagnosis was reached through cytologic biopsy, or histopathologic tests (or all of these). RESULTS One hundred thirty lesions were found. With regard to the distribution of the lesions, 116 (89%) were single; 14 (3%) were multiple, with 118 (91%) in the right lobe and 12 (9%) in the left lobe; 83 (64%) were posterior; and 47 (36%) were anterior. With respect to the pattern of radioactivity fill-in, 86 (66%) lesions were typical and 44 (34%) were atypical. The results of Tc-99m RBC scintigraphy showed sensitivity, specificity, and positive and negative predictive and accuracy values of 97%, 83%, 98%, 77%, and 96% respectively. The use of SPECT improved the sensitivity value by 11% for lesions of 1 to 2 cm. CONCLUSIONS Tc-99m RBC scintigraphy is the noninvasive technique most helpful in the diagnosis of hepatic hemangioma, especially in those at risk for lesion rupture or bleeding. SPECT should be performed whenever planar imaging fails to show the lesion by 2 hours. The use of ultrasound should precede scintigraphy for two important reasons: the size and the location of the lesion. Location of the lesion (anterior or posterior) is important for optimal gamma camera acquisition parameters. Lesions less than 1 cm are cannot be detected because they are beyond the limit of spatial resolution of the gamma camera we used.
Collapse
|
33
|
Radionuclide esophageal transit time for the assessment of pneumatic dilation in patients with achalasia. Saudi J Gastroenterol 1999; 5:71-5. [PMID: 19864747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
OBJECTIVE The aim of this study was to assess the value of radionuclide esophageal transit time (RET) in prediction of the results of pneumatic dilation in patients with achalasia. PATIENTS AND METHODS Thirty patients (13 males) with a mean age of 37 +/- 15.6 years (range 17-73 years) were included in the study. All patients were diagnosed to have idiopathic achalasia of the cardia and selected for pneumatic dilation. Each patient had three RET, two the same day of dilation (pre-and postdilation) and a third follow up one within three months of dilation (4 patients failed to come for follow up and were excluded). RESULTS Several parameters were derived from RET studies, T/50: time required for 50% of activity in the esophagus to be cleared, T/10 : time required for 90% of activity in the esophagus to be cleared and percentage clearance at 10 min. These parameters were compared to response of dysphagia to dilation. It was evident that the higher the esophageal clearance postdilation, the better the outcome. When immediate post dilation clearance was 85% or more the success rate was 83.3% whereas when it was 20-50% the success rate was only 21.4%. No relation was found between T/50, T/10 and dysphagia response. CONCLUSION RET appears to be a useful quantitative procedure in the assessment of pneumatic dilation outcome in achalasia patients.
Collapse
|
34
|
Purification, redox and spectroscopic properties of the tetraheme cytochrome c isolated from Rubrivivax gelatinosus. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 261:325-36. [PMID: 10103066 DOI: 10.1046/j.1432-1327.1999.00277.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The tetraheme cytochrome c subunit of the Rubrivivax gelatinosus reaction center was isolated in the presence of octyl beta-D-thioglucoside by ammonium sulfate precipitation and solubilization at pH 9 in a solution of Deriphat 160. Several biochemical properties of this purified cytochrome were characterized. In particular, it forms small oligomers and its N-terminal amino acid is blocked. In the presence or absence of diaminodurene, ascorbate and dithionite, different oxidation/reduction states of the isolated cytochrome were studied by absorption, EPR and resonance Raman spectroscopies. All the data show two hemes quickly reduced by ascorbate, one heme slowly reduced by ascorbate and one heme only reduced by dithionite. The quickly ascorbate-reduced hemes have paramagnetic properties very similar to those of the two low-potential hemes of the reaction center-bound cytochrome (gz = 3.34), but their alpha band is split with two components peaking at 552 nm and 554 nm in the reduced state. Their axial ligands did not change, being His/Met and His/His, as indicated by the resonance Raman spectra. The slowly ascorbate-reduced heme and the dithionite-reduced heme are assigned to the two high-potential hemes of the bound cytochrome. Their alpha band was blue-shifted at 551 nm and the gz values decreased to 2.96, although the axial ligations (His/Met) were conserved. It was concluded that the estimated 300 mV potential drop of these hemes reflected changes in their solvent accessibility, while the reduction in gz indicates an increased symmetry of their cooordination spheres. These structural modifications impaired the cytochrome's essential function as the electron donor to the photooxidized bacteriochlorophyll dimer of the reaction center. In contrast to its native state, the isolated cytochrome was unable to reduce efficiently the reaction center purified from a Rubrivivax gelatinosus mutant in which the tetraheme was absent. Despite the conformational changes of the cytochrome, its four hemes are still divided into two groups with a pair of low-potential hemes and a pair of high-potential hemes.
Collapse
|
35
|
Distinct structures and environments for the three hemes of the cytochrome bc1 complex from Rhodospirillum rubrum. A resonance Raman study using B-band excitations. Biochemistry 1999; 38:1066-76. [PMID: 9894003 DOI: 10.1021/bi9805487] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The B-band excited resonance Raman (RR) spectra (100-1700 cm-1) of the bacterial cytochrome bc1 complex purified from Rhodospirillum rubrum are reported. Four redox states, i.e., the persulfate-oxidized, "as prepared", and ascorbate- and dithionite-reduced states of the complex, were investigated with the laser excitations at 406.7, 413.1, and 441.6 nm. Following the different absorption properties of the b- and c-type hemes and the different resonance enhancements of the vibrational modes of oxidized and reduced hemes, RR contributions from the b- and c-type hemes were characterized. For the nu2, nu10, and nu8 porphyrin vibrational modes, individual contributions of hemes c1, bH, and bL were determined. The data show that the macrocycle conformation of the three hemes of the cytochrome bc1 complex is different. In particular, the frequencies assigned to ferrous heme bL (1580, 1610, and 352 cm-1, respectively) reveal that its porphyrin is more strongly distorted than that of ferrous heme bH (1584, 1614, and 344 cm-1, respectively). The frequencies of the nu11 modes (1543, 1536, and 1526 cm-1 for ferrous heme c1, heme bH, and heme bL, respectively) confirm that the axial histidylimidazole ligands of heme bL have a marked anionic character. Strong differences in the peripheral interactions of the three hemes with the proteins were also detected through the frequency differences of the nu5, nu13, nu14, and nu42 modes. Considering that hemes bH and bL are inserted into a four-helice bundle, the RR data are interpreted in the frame of a strong protein constraint on heme bL.
Collapse
|
36
|
On-Line Monitoring and Modelling of Free Radical Copolymerisations: Butyl Acrylate/Vinyl Acetate. ACTA ACUST UNITED AC 1999. [DOI: 10.1080/10543414.1999.10744498] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
37
|
TC-99m-labeled red blood cell scintigraphy in the investigation of patients with hepatic cavernous hemangioma. Saudi J Gastroenterol 1999; 5:27-31. [PMID: 19864757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
OBJECTIVE To evaluate the diagnostic accuracy of 99mTc-red blood cell scintigraphy in the diagnosis of hepatic cavernous hemangiomas. PATIENTS AND METHODS Sixty three patients, 56 females (89%) and 7 males (1 I%), with ages between 22 and 54 years (median 33 years) were investigated for liver masses found on ultrasonography of the abdomen. All the patients had undergone 99mTc-liver-spleen scan followed by 99mTc-red blood cells scintigraphy. The size of the lesions ranged between 3 and 9 cm. The final diagnosis was reached through cytology, and/or histopathology or follow up for more than 3 years. RESULTS A total of 70 lesions were found as a single lesion in 60 patients and multiple (i.e. total of 10 lesions) in the other 3 patients. The results of 99mTc-red blood cells scintigraphy, compared to the results of the final diagnosis, showed sensitivity and specificity rates of 100% and 89% respectively, positive and negative predictive values of 98% and 100% respectively, and accuracy rate of 98.6%. A single false positive case was a hepatocellular carcinoma. CONCLUSION 99mTc- red blood cell scintigraphy is highly accurate in the diagnosis of liver cavernous hemangioma and should characterize liver mass found on ultrasonography and suspected for hemangioma.
Collapse
|
38
|
Resonance Raman investigation of lysine and N-acetylmethionine complexes of ferric and ferrous microperoxidase. EUROPEAN BIOPHYSICS JOURNAL: EBJ 1998. [DOI: 10.1007/s002490050179] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
39
|
Hepatobiliary scintigraphy in the distinction between biliary hypoplasia and biliary atresia. Saudi J Gastroenterol 1998; 4:8-12. [PMID: 19864779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
The aim of this work is to see whether distinction between biliary atresia and biliary hypoplasia is possible or not and to present the value and usefulness of hepatobiliary scintigraphy in the investigation of infants with persistent hyperbilirubinemia. Seventy-seven patients of the age between five days and six months (average 62 days), 43 females and 34 males of which 65 Saudi, and 12 non-Saudis were investigated. Laboratory tests, abdominal ultrasound, hepatobiliary scintigraphy, liver biopsy, explorative laparatomy and intraoperative cholangiography were performed whenever indicated. The findings on hepatobiliary scintigraphy of nonvisualization of the gallbladder and no activity in the bowel upto 24 hours post injection were considered consistent with the diagnosis of biliary atresia. Minimal bowel activity, or visualization of the gallbladder where consistent with biliary hypoplasia. In addition, the liver in the two entities appeared in a different shape and can be used as an additional distinctive feature. Thirty-four infants were diagnosed by hepatobiliary scintigraphy as having biliary atresia. Only 3 of the 34 were false positives as compared to cholangiogram and liver biopsy results. Five cases were biliary hypoplasia. Hepatobiliary scintigraphy in infants with persistent hyperbilirubinemia can be distinguished between BA and BH in a simple and noninvasive approach.
Collapse
|
40
|
|
41
|
Influence of conserved amino acids on the structure and environment of the heme of cytochrome c2. A resonance Raman study. Biochemistry 1997; 36:5499-508. [PMID: 9154933 DOI: 10.1021/bi962584g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Resonance Raman spectra using Soret excitations of oxidized and reduced Rhodobacter capsulatus cytochrome c2 at pH 7.5 were studied. The spectra of oxidized cytochrome c2 show three components for the v10 mode at 1638, 1633, and 1629 cm(-1). The intensities of these components are sensitive to the excitation wavelength. This effect is explained in the context of a conformational equilibrium of the ferriheme between a nearly planar structure and two ruffled structures. In the case of reduced cytochrome c2, the absolute frequencies as well as the excitation-dependent frequency dispersion of the v10 mode (1618-1621 cm(-1)) indicate a displacement of the conformational equilibrium of heme toward the more planar structures. To measure the influence of some key amino acid residues on the heme-protein interaction of cytochrome c2, four site-directed mutants of Rb. capsulatus cytochrome c2 have been studied by resonance Raman spectroscopy and their spectra compared with the spectra obtained for the wild type cytochrome. The mutants studied are K14E/K32E, P35A, W67Y, and Y75F. The spectral changes induced by the mutations are interpreted in terms of alterations in the structure and/or environment of the cytochrome c2 heme in the framework of the expected role of the different amino acid residues in the stability and redox potential.
Collapse
|
42
|
Hemiconvulsion-hemiplegia-epilepsy syndrome. A clinical, electroencephalographic and neuroradiological study. Childs Nerv Syst 1997; 13:257-63. [PMID: 9224914 DOI: 10.1007/s003810050079] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Six patients (4 boys and 2 girls) with hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome are described. They had prolonged seizures, lasting from 30 min to 12 h, at ages 1-4 years. These took the form of hemiconvulsion in three of the children and generalized tonic-clonic seizures in the others, being preceded by hemifacial twitching or head and eye deviation in two. They were followed by hemiplegia, which cleared with time in five patients, apart from subtle pyramidal tract signs. One child had spastic quadriparesis, choreiform movements, contracture deformities and severe mental retardation following repeated status epilepticus. Subsequent epilepsy developed in five patients and was satisfactorily controlled with carbamazepine and/or phenobarbitone. Cerebral hemiatrophy was documented in all patients by cranial computed tomography and/or magnetic resonance imaging. Single photon emission computed tomography (done in 4 patients) showed ipsilateral hypoperfusion (of the damaged hemisphere). Electroencephalography showed ipsilateral slowing and low voltage of background activity. Epileptiform discharges were found on the ipsilateral side in two cases and the contralateral side (the undamaged hemisphere) in one.
Collapse
|
43
|
Hepatobiliary scintigraphy in the diagnosis of choledochal cysts in children. Saudi J Gastroenterol 1997; 3:78-83. [PMID: 19864798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
The objective is to present the usefulness of hepatobiliary scintigraphy in the investigation of children with suspected choledochal cysts through our experience in King Khalid University Hospital at King Saud University, Riyadh. Seven patients aged between I and 10 years (average 4.8 yrs) comprising six females and one male were investigated. Laboratory tests, abdominal Ultrasound and/or CT, and cholangiography were performed whenever indicated. Persistent activity in a dilated common bile duct, with or without dilatation of intrahepatic bile ducts, was considered a positive indicator for choledochal cyst disease. Four children with cystic dilatation (type I) were diagnosed by hepatobiliary scintigraphy, one saccular (type II), and two cases of Caroli's disease (type V). The diagnosis of choledochal cyst was proven by surgery with histological confirmation. Visualization of the gallbladder occurred in one case only. The common bile duct was seen in four cases. Late activity in the bowel was noted in two cases.
Collapse
|
44
|
A nonlinear approach for the on-line estimation of the kinetic rates in bioreactors. ACTA ACUST UNITED AC 1997. [DOI: 10.1007/s004490050368] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
45
|
Serotypes of group A streptococci isolated from healthy schoolchildren in the United Arab Emirates. Bull World Health Organ 1997; 75:355-9. [PMID: 9342894 PMCID: PMC2486967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Group A streptococci (GAS) are the most frequent cause of pharyngitis in children and are a common cause of emergency room or paediatric clinic visits worldwide. This study determined the representative M and T types of GAS, and their distribution, among schoolchildren in the United Arab Emirates. Throat swabs were taken and cultured for GAS isolates during the winter of 1994-95 from 1000 children aged 5-7 years attending nine schools. Of the isolates obtained, 100 were serotyped using standard techniques. Nearly all these isolates (91%) were T typable, falling into 15 T types; the commonest being type 1 (n = 17), type 6 (n = 15), type 11 (n = 10), type 2 (n = 8), type 12 (n = 8), and type 28 (n = 8). A total of 76% of the isolates were typable for M protein, falling into 14 M types, with type 1 (n = 17), type 6 (n = 15), type 2 (n = 8), type 22 (n = 5), type 28 (n = 7), and type 75 (n = 5) predominating. Serotype clusters were found in certain classes or schools, although the number of isolates examined was too small to allow definitive epidemiological conclusions to be drawn. The ease of serotyping these isolates suggests that GAS strains in the United Arab Emirates are similar, but not necessarily related, to those commonly found in the USA and Europe, and that these may be the most prevalent strains worldwide. The relative prevalence of M type 1 is significant, as this GAS serotype is associated with serious diseases such as rheumatic heart disease, a recognized problem in the United Arab Emirates, and toxic shock syndrome, which has not yet been reported from this area. Knowledge of the prevalence of GAS serotypes, and further research on the epidemiology of streptococcal disease, will be useful should streptococcal vaccines become available.
Collapse
|
46
|
Evidence for a proximal histidine interaction in the structure of cytochromes c in solution: a resonance Raman study. Biochemistry 1996; 35:9224-34. [PMID: 8703928 DOI: 10.1021/bi952818g] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Soret-excited resonance Raman (RR) spectra of oxidized and reduced cytochromes ć from Rhodospirillum molischianum and Rhodobacter sphaeroides, in solution, are reported. The spectra of the type I ferricytochromes ć in both species contain different extents of two forms. One of these is readily assignable to a "normal" five-coordinated high-spin heme. The second species with v3 and v10 modes at 1502 and 1635 cm-1, respectively, is attributed to a five-coordinated intermediate-spin heme. The RR data show that the equilibrium between these two forms is species-dependent at neutral pH and 20 degrees C. The v(Fe-His) mode of the a form of reduced cytochromes ć is assigned to a band at 228-231 cm-1, indicating that the proximal His has a strong electronegative character. X-ray crystallographic data on R. molischianum ferricyt ć show that the proximal His has no interaction with either the protein or water molecules [Finzel, B.C., Weber, P.C., Hardman, K.D., & Salemme, F.R.(1985) J. Mol. Biol. 186, 627-643]. Considering that the absence of H bonding at the coordinated histidine corresponds to a low frequency for the v(Fe-His) mode (195-205 cm-1), the structure and/or environment of the proximal histidine appears different for cyt ć (III) in the crystal and cyt ć (II) in aqueous solution. To account for the elevated frequency of the v(Fe-His) mode of cyt ć (II), several possibilities have been examined. Among these, we propose that a conserved Lys residue, located in the protein sequence three residues before the His ligand, can form an electrostatic interaction with the (His)N1 atom, directly or through a water molecule. It is further suggested that this electrostatic interaction could also play a role in the high-spin <--> intermediate-spin equilibrium of oxidized cytochromes ć.
Collapse
|
47
|
Abstract
The clinical and biochemical features of postpartum thyroid disease were analysed in 152 antithyroid peroxidase antibody-positive (anti-TPO+ve) women and compared with 239 anti-TPO-ve age-matched control postpartum women. All were assessed monthly for up to 12 months postpartum. Seventy three anti-TPO+ve women developed postpartum thyroiditis (PPT): 19.2% hyperthyroid alone, 49.3% hypothyroid alone, and 31.5% characterized by hyper- followed by hypothyroidism. None of the antibody-negative women developed any thyroid dysfunction. A significant increase in many of eleven symptoms of hypothyroidism and some of eight symptoms of hyperthyroidism compared to control women was observed in all anti-TPO+ve women, independent of thyroid status. This was particularly seen in women who later developed PPT when they were euthyroid, but was also observed in euthyroid anti-TPO+ve women who showed no decline of thyroid function during the postpartum period. Although PPT is usually transient, this condition, and the euthyroid antibody-positive state, may be associated with significant symptomatology, including an increased incidence of minor to moderate depression. Early recognition of this syndrome by antenatal screening of thyroid antibodies may contribute to improved management of women during the postpartum period.
Collapse
|
48
|
The role of complement in the pathogenesis of postpartum thyroiditis: ultrasound echogenicity and the degree of complement-induced thyroid damage. Thyroid 1996; 6:177-82. [PMID: 8837323 DOI: 10.1089/thy.1996.6.177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Postpartum thyroiditis (PPT) is a transient autoimmune thyroiditis occurring during the postpartum year that is characterized by circulating antithyroid antibodies, abnormal thyroid ultrasound echotexture, and episodes of hyperthyroidism, hypothyroidism, or both. In this study we examined the relationship between lymphocytic thyroiditis, as indicated by echotexture changes, and complement-activating thyroid autoantibodies. Thyroid ultrasound echotexture, thyroid function, and bioactive (complement-activating) thyroid peroxidase (TPO) antibodies have been measured in a group of 63 TPO antibody-positive women during the postpartum year. When the maximum bioactive TPO antibody activity recorded was compared with echogenicity and thyroid status, there was a correlation between hypoechogenicity, elevated antibody activity, and abnormal thyroid status (r = 0.72, p < 0.001). However, 7 cases showed severe ultrasound changes in the absence of any thyroid dysfunction (3 of these cases showed normal bioactive antibody activity), while 4 (all hyperthyroid PPT) showed thyroid dysfunction in the absence of any ultrasound changes. Within the euthyroid ultrasound normal group, bioactive TPO antibody activity remained low throughout the postpartum year. Antibody activity in the hypoechogenic euthyroid women was significantly elevated (p < 0.001) compared with the echo normal group, but was indistinguishable from the activity curve obtained in women whose PPT included a hypothyroid phase. The determination of echotexture by thyroid ultrasonography gives a useful, noninvasive measure of the degree of thyroiditis in these women. However, as a significant number of cases with severe changes in echotexture remained euthyroid, we conclude that the development of thyroid dysfunction is not an inevitable consequence of lymphocytic thyroiditis during the postpartum and suggests that other factors must also be involved in progression to overt thyroid dysfunction.
Collapse
|
49
|
Abstract
The objective was to re-evaluate the association between class II HLA-DR and DQ MIIC antigens and postpartum thyroiditis (PPT) and to determine the prevalence of the class III complement allotypes of Properdin factor B (Bf), C4A and C4B in this condition. Two hundred and sixty-five (of 2897) pregnant women screened positive for thyroid autoantibody activity took part. Further blood samples were obtained for HLA class II (185) and complement (193) typing. The severity of the ensuing PPT was assessed by measuring thyroid function during the postpartum year. The HLA-DR and DQ phenotypes were assigned from restriction fragment length polymorphism analysis, and Bf, C4A and C4B allotypes were determined by immunofixation with anti-Bf or anti-C4 antibodies after electrophoresis. A weak association between the HLA class II antigens and PPT, as indicated by a reduced frequency of DR15 and DQ6 together with an increased frequency of-DR5 and DQ7, was confirmed. However, only the change in DR5 frequency remained significant after correction (corrected p < 0.05). Postpartum thyroiditis was also associated with frequency disturbances in BI and C4A allotypes but not C4B allotypes. Whilst this study has not provided evidence of a strong marker gene for PPT, it does not preclude the involvement of the MIIC in this condition. These data show disturbances in complement allotype frequencies, suggesting that the class III region may provide a useful focus for further study of this pathology.
Collapse
|
50
|
Role of complement in the pathogenesis of postpartum thyroiditis: relationship between complement activation and disease presentation and progression. Eur J Endocrinol 1995; 133:210-5. [PMID: 7655646 DOI: 10.1530/eje.0.1330210] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The aim of this study was to assess whether the presentation and progression of autoimmune postpartum thyroiditis (PPT) was related to the degree of thyroid peroxidase autoantibody (TPO-ab)-mediated activation of the complement cascade. One hundred and forty-eight thyroid autoantibody-positive women have been followed during their postpartum year. Seventy-five women remained euthyroid during this time whilst the remaining 73 showed one or more episodes of thyroid dysfunction. Fourteen women showed hyperthyroid PPT, 23 showed a biphasic PPT and the remaining 36 showed hypothyroid PPT. Hyperthyroid PPT was always transient but 29 of the 59 women with hypothyroidism remained hypothyroid or still required thyroxine replacement therapy at the conclusion of the study. Thyroid autoantibodies were measured by enzyme-linked immunosorbent assay (ELISA), free triiodothyronine and free thyroxine by the Amerlex M methods and thyrotrophin by the Amerlite TSH (monoclonal) assay. Complement component C3b, immobilized as a result of classical complement pathway activation in the presence of TPO/TPO-ab complexes in vitro, was measured by ELISA. Bioactive TPO-ab were calculated as the product of the C3 index and TPO-ab level. Basal levels of complement C3 activation were seen in the euthyroid TPO-ab-positive women (C3 index 0.06 at delivery rising to 0.36 at 12 months postpartum; bioactive TPO-ab activity 0.4 kIU/l at delivery rising to 10.4 kIU/l at 12 months' postpartum (N = 75). These parameters were elevated progressively as the severity of the clinical syndrome increased. In 14 hyperthyroid PPT women the C3 index was 0.47 at 8 months' postpartum (bioactive TPO-ab activity = 20 kIU/I; p vs euthyroid group, NS).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|