Medical response to the 2009 Sumatra earthquake: health needs in the post-disaster period.

INTRODUCTION: This paper provides an overview of cases seen by the Singapore Armed Forces (SAF) medical and surgical teams in the 2009 Sumatra earthquake and discusses the role of militaries in the acute phase of a disaster. METHODS: Two SAF primary healthcare clinics prospectively collected patient medical information for comparison. Descriptive analysis of the Emergency Department (ED) and surgical case records was performed. RESULTS: 1,015 patients were seen by the two primary healthcare clinics. In both Koto Bangko and Pariaman, respiratory-related conditions were the most common diagnoses (47.2% and 30.6%, respectively), followed by musculoskeletal/joint conditions (31.6% and 20.6%, respectively). In the ED, 55% and 27% of the 113 patients had trauma-related and infective-related diagnoses, respectively. Lacerations and contusions were the most common forms of trauma. Lung infection was the most common infective diagnosis seen at the ED. The number of ED cases was high during the first week and gradually declined in the second week. 56% of the 102 surgical procedures were performed on dirty or infective wounds. Fractures requiring fixation comprised 38% of surgical procedures. CONCLUSION: Medical aid remains an important component of the overall humanitarian response. Militaries could play an important role in disaster response due to their ability to respond in a timely fashion and logistic capabilities. Pre-launch research on the affected area and knowledge on disaster-specific injury patterns would impact the expertise, equipment and supplies required. The increasing evidence base for disaster preparedness and medical response allows for better planning and reduces the impact of disasters on affected populations.

Singapore Armed Forces Medical Corps-Ministry of Health clinical practice guidelines: management of heat injury.

The Singapore Armed Forces (SAF) Medical Corps and the Ministry of Health (MOH) have published clinical practice guidelines on Management of Heat Injury to provide doctors and patients in Singapore with evidence-based guidance on the prevention and clinical management of exertional heat injuries. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the SAF Medical Corps-MOH clinical practice guidelines on Management of Heat Injury, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/mohcorp/publications.aspx?id=25178. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Hypertension in young adults--an under-estimated problem.

AIM: To study the prevalence of hypertension and "white coat hypertension" in young adult Asian males, and identify the associated risk factors. METHODS: Population-based descriptive analysis of 3,352 Singapore military conscripts presenting consecutively for medical screening, followed by case-control study of subjects with elevated blood pressure. A standard protocol for assessing elevated blood pressure, 24-hour ambulatory monitoring and detailed interviews were performed. Main study outcomes are prevalence rate of hypertension and "white coat hypertension", mean blood pressure readings, and adjusted odds ratios for associated variables. RESULTS: Prevalence of hypertension and "white coat hypertension" was 1.6% (95% CI 1.2, 2.0) and 2.0% (95% CI 1.5, 2.5) respectively. Twenty-four-hour ambulatory monitoring was required to differentiate the two conditions, with a fall of 22.5 mmHg (95% CI 19.7, 25.3) observed between first visit and day-time ambulatory mean systolic blood pressures. There was strong association between hypertension and obesity (adjusted odds ratio using Body Mass Index: 1.19, p<0.001). Other important variables included parental history of hypertension, Malay ethnicity and low socio-economic status, although there was no significant correlation in our regression model. CONCLUSION: This study provides population-based data on hypertension in young Asian adults. While the prevalence of hypertension is low compared to older age groups, it remains important to detect cases early, as appropriate treatment may mitigate long-term cardiovascular risks and reduce target organ damage. There is a clear role for ambulatory blood pressure monitoring for differentiating true hypertension from "white coat hypertension". There may be a role for targeted screening of high-risk groups, particularly the obese.

Prevalence of hearing disorders in Singapore military conscripts: a role for routine audiometry screening?

AIM: To determine the prevalence of hearing disorders in Singapore military conscripts and describe the profile of hearing loss and associated risk factors. METHODS: Population-based descriptive analysis of randomised cohort of 818 Singapore military conscripts presenting for medical examination, using self-administered questionnaire and pure tone audiometry performed for both ears. Main outcome measures are prevalence rate of hearing loss and relative risk of hearing loss by demographic factors and surrogates for noise exposure. RESULTS: Prevalence of hearing loss was 36.7 per 1,000 (95% CI 24.8, 51.9). Of 30 subjects with hearing loss, 19 (63.3%) had loss at high frequency, 7 (23.3%) at low frequency, and 4 (13.4%) in both ranges. Hearing loss was unilateral in 17 (56.7%) subjects and bilateral in 13 (43.3%). Relative risk of hearing loss did not differ by age group, education level, race or frequency of personal stereo use. Relative risk of hearing loss is higher in subjects with frequent discotheque visits compared to those who never do so (RR = 2.72, 95%CI 1.09, 6.76). CONCLUSION: The high prevalence of hearing loss in Singapore military conscripts points to the need for routine audiometry screening prior to enlistment. This will be useful in assigning military vocations, in clinical case management, and for assessing cases of noise-induced hearing loss attributable to military service.

Molecular determinants for CC-chemokine recognition by a poxvirus CC-chemokine inhibitor.

Poxviruses express a family of secreted proteins that bind with high affinity to chemokines and antagonize the interaction with their cognate G protein-coupled receptors (GPCRs). These viral inhibitors are novel in structure and, unlike cellular chemokine receptors, are able to specifically interact with most, if not all, CC-chemokines. We therefore sought to define the structural features of CC-chemokines that facilitate this broad-spectrum interaction. Here, we identify the residues present on human monocyte chemoattractant protein-1 (MCP-1) that are required for high-affinity interaction with the vaccinia virus 35-kDa CC-chemokine binding protein (VV-35kDa). Not only do these residues correspond to those required for interaction with the cognate receptor CCR2b but they are also conserved among many CC-chemokines. Thus, the results provide a structural basis for the ability of VV-35kDa to promiscuously recognize CC-chemokines and block binding to their receptors.

Military laser weapons: current controversies.

Military laser weapons systems are becoming indispensable in most modern armies. These lasers have undergone many stages of development, and have outpaced research on eye protection measures, which continue to have inherent limitations. Eye injuries caused by military lasers are increasingly reported, leading to speculation that these would become an important cause of blinding in modern conflicts. As part of the effort to ban inhumane weapons, international laws have been passed to restrict the proliferation of such blinding weapons. However, there are controversies concerning the interpretation, implementation and effectiveness of these laws. The ophthalmic community can play a greater role in highlighting ocular morbidity from military lasers, and in preventing their further proliferation.

Academic achievement, close up work parameters, and myopia in Singapore military conscripts.

AIM: To determine the relation of refractive error to environmental factors, including close up work, in Singapore military conscripts. METHODS: A cross sectional study was conducted on 429 Singapore military conscripts. Non-cycloplegic refraction and A-scan biometry were performed in both eyes. A detailed questionnaire was administered by in-person interview to obtain information about current and past near work activity, extra tuition lessons, educational experiences, and family demographics. RESULTS: Myopia associated with the conscript having been educated in the (gifted, special, or express) educational streams (adjusted odds ratio (OR) = 3.8, 95% confidence interval CI 2.0-7.3), and having completed pre-university education (OR=4.1, 95% CI 1.9-8.8). The reported close up work activity at age 7 years did correlate with age of onset of myopia (p<0.001). In parallel, supplemental tuition lessons in primary school has (OR=2.6, 95% CI 1.4-4.9) associated with conscript myopia. Parental myopia was positively associated with myopia (p<0.001), but this relation disappeared when adjusted for environmental factors. Current (p=0.83) and past close up work activity at age 7 years (p=0.13) did not correlate with myopia. CONCLUSION: Educational level and educational stream positively related to myopia. A relation was observed with reported close up work activity in early childhood and with tuition classes during elementary school, but not with current close up work activity. These results underscore the strong influence of environment in myopia pathogenesis but a role for close up work activity remains indeterminate.

Glycosaminoglycan binding properties of the myxoma virus CC-chemokine inhibitor, M-T1.

Poxviruses encode a number of secreted virulence factors that function to mitigate or modulate the host immune response. M-T1 is a secreted 43-kDa glycoprotein produced by the myxoma virus, a poxvirus pathogen of rabbits, that binds CC-chemokines with high affinity, blocks binding to their cognate G-protein coupled receptors, and thereby inhibits chemokine-induced leukocyte chemotaxis. The present study indicates that M-T1, but not the related vaccinia virus 35-kDa CC-chemokine-binding protein, can localize to cell surfaces through an interaction with glycosaminoglycan molecules. In addition to biochemically characterizing the nature of this interaction, we demonstrate that M-T1 can also simultaneously interact with CC-chemokines while bound to heparin, suggesting that the binding sites on M-T1 for chemokines and heparin are distinct. Furthermore, using recombinant baculovirus-expressed M-T1 truncation and internal deletion mutants, we localize the heparin-binding region of M-T1 to the C terminus of the protein, a region that contains a high abundance of basic residues and includes two clusters of basic amino acid residues that resemble Cardin and Weintraub heparin-binding consensus sequences. The ability of M-T1 to simultaneously interact with chemokines and glycosaminoglycans may enable M-T1 to tether to endothelial surfaces or extracellular matrix and capture host chemokines that are expressed close to sites of virus infection.

Does education explain ethnic differences in myopia prevalence? A population-based study of young adult males in Singapore.

PURPOSE: To study interethnic variation in myopia prevalence and severity in young adult males in Singapore and to determine whether these variations are related to differences in education level. METHODS: A population-based survey of refractive errors in a cohort of 15,095 military conscripts between July 1996 and June 1997 using noncycloplegic autorefraction and a standard questionnaire. Prevalence rates of myopia (<-0.5 D) and severe myopia (<-6.0 D) were determined for Chinese, Malay, and Indian men; prevalence rate ratios were compared after adjusting for education level. RESULTS: Singapore has one of the highest prevalences of myopia (79.3%) and severe myopia (13.1%), with Chinese having higher rates (82.2%, 95% confidence interval 81.5, 82.9) compared with Indians (68.7%, 95% confidence interval 65.1, 67.1) and Malays (65.0%, 95% confidence interval 62.9, 67.1). Education was strongly associated with prevalence and severity of myopia. However, significant interethnic variation persisted after adjusting for education. CONCLUSIONS: There is a high prevalence of myopia in Singapore. Although prevalence and severity of myopia were strongly associated with education, interethnic variation observed was not fully explained by differences in education level.

Regulation of nitric oxide synthase 2 in rabbit corneal cells.

PURPOSE: The purpose of these studies was to investigate the role of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), and transforming growth factor-beta (TGF-beta) in the regulation of inducible nitric oxide synthase (NOS2) activity in rabbit corneal cells. METHODS: Rabbit corneal epithelial, stromal, and endothelial cells were grown in culture and treated with cytokines and growth factors, alone or in combination. NOS activity was measured at times up to 72 hours after treatment by assaying the culture medium for nitrite using the Griess reaction. Cell lysates were analyzed by Western blot analysis for NOS2 protein. RNA was isolated and amplified with NOS1-, NOS2-, and NOS3-specific primers by RT-PCR. RESULTS: NOS2 expression was induced by combined cytokine treatment from nondetectable levels to abundant levels in low passage (<4) stromal cells and to low levels in corneal endothelial cells but not in corneal epithelial cells. In the absence of IFN-gamma, little or no nitrite accumulation was induced by TNF-alpha, IL-1beta, or lipopolysaccharide (LPS) treatment. The inductive effects of IFN-gamma were antagonized in a dose-dependent manner by the myxoma virus rabbit IFN-gamma receptor homolog, M-T7. rRaIFN-gamma, in combination with IL-1beta and TNF-alpha, induced the appearance of NOS2 mRNA within 24 hours but detectable nitrite did not accumulate in large amounts (>10 microM) until after 24 hours postinduction. NOS2 was identified as a 130 kDa protein on Western blot analysis using monoclonal antibody against murine NOS2. TGF-beta(1) and beta(2) inhibited the accumulation of cytokine-induced nitrite in a dose-dependent manner while not significantly reducing the steady state level of NOS2 mRNA. The activity of the induced NOS was inhibited by 1400W, a NOS2-selective inhibitor, but not 7-nitroindazole, a NOS1-selective inhibitor. CONCLUSIONS: In cultured corneal stromal cells, NOS2 expression was upregulated by IFN-gamma in combination with IL-1beta and TNF-alpha but not by any of these cytokines alone, while TGF-beta downregulated the activity. Cultures of corneal epithelial cells could not be induced to express NOS2, yet cultures of endothelial cells produced low amounts of NO in response to cytokines. The NOS1 and NOS3 isoforms were not detected in any of these corneal cells.

Fatality trends in United Nations Peacekeeping Operations, 1948-1998.

CONTEXT: The rising number of deaths among United Nations (UN) peacekeeping forces after the Cold War has made some troop-contributing countries hesitant to participate in peacekeeping operations. While the number and scale of missions have increased, no data have demonstrated a parallel increase in risks to peacekeepers. OBJECTIVE: To determine the association of characteristics of UN peacekeeping operations with risks and mortality rates among UN peacekeeping forces in both the Cold War and post-Cold War periods. DESIGN, SETTING, AND PARTICIPANTS: Descriptive analysis of 1559 personnel deaths during 49 UN peacekeeping missions from 1948-1998 based on the casualty database maintained by Department of Peacekeeping Operations, UN Headquarters. MAIN OUTCOME MEASURES: Number and percentage of deaths by circumstance, total crude death rate, and crude death rate and relative risk of death by circumstance (hostile acts, unintentional violence, and illness or other causes) and time period (Cold War vs post-Cold War), geographic region, and nature of peacekeeping response; and regression analysis of mission variables (strength, duration, and humanitarian mandate) associated with total number of deaths. RESULTS: More deaths have occurred among UN peacekeeping forces in the past decade alone than in the previous 40 years of UN peacekeeping (807 vs 752), but crude death rates did not differ significantly by time period (Cold War vs post-Cold War, 21.8 vs 21. 2 deaths per 10,000 person-years; P =.58), level of peacekeeping response, or for geographic regions other than East Europe and Central America, where rates were lower (P<.001 for both regions). Unintentional violence accounted for 41.2% of deaths, followed by hostile acts (36.1%), and illness or other causes (22.7%). Deaths from hostile acts increased after the Cold War (relative risk [RR] 1. 51; 95% confidence interval [CI], 1.22-1.88), while rates for deaths caused by unintentional violence decreased (RR, 0.79; 95% CI, 0.67-0. 94) but remain high, particularly in the Middle East and Asia (RR, 1. 39; 95% CI, 1.15-1.69). Regression analysis showed a significant association between number of deaths and the strength (P<.001) and duration (P<.001) of a peacekeeping mission. CONCLUSION: The increase in number of deaths among UN peacekeeping personnel since 1990 can be attributed to the increased number and scale of missions after the Cold War rather than increased RR of death. Post-Cold War peacekeeping personnel have a higher risk of dying from hostile acts in missions where more force is required. In missions providing or facilitating humanitarian assistance, both the RR of deaths from all causes and deaths from hostile acts are increased. JAMA. 2000;284:598-603

The viral anti-inflammatory chemokine-binding protein M-T7 reduces intimal hyperplasia after vascular injury.

Chemokines and IFN-gamma function as central regulators of inflammatory responses to vascular injury. Both classes of cytokines are upregulated during restenosis, a response to vascular injury that leads to recurrent atherosclerotic plaque growth, but the relative impact of each class of cytokines remains undetermined. M-T7 is a secreted myxoma viral immunomodulatory glycoprotein that functions both as a species-specific inhibitor of rabbit IFN-gamma and as a chemokine-binding protein, interacting with a wide range of C, C-C, and C-X-C chemokines in a species-nonspecific fashion. We wished to (a) assess the efficacy of purified M-T7 protein in inhibiting intimal hyperplasia after angioplasty injury and (b) exploit unique species-specific functions of M-T7 in order to judge the relative importance of each cytokine class on plaque growth. Anesthetized New Zealand white rabbits and Sprague-Dawley rats received either M-T7 or control at the time of arterial angioplasty injury. Histological analysis at 28 days demonstrated significant reductions in intimal hyperplasia with M-T7 treatment in both models, with an associated early inhibition of inflammatory cell invasion. Purified M-T7 protein inhibits intimal hyperplasia after angioplasty injury in a species-nonspecific fashion, thus implicating the chemokine-binding activity as more critical for prevention of plaque growth after vascular injury.

Post-translational modification of the myxoma-virus anti-inflammatory serpin SERP-1 by a virally encoded sialyltransferase.

SERP-1 is a secreted serpin (serine-proteinase inhibitor) encoded by myxoma virus, a poxvirus pathogen of rabbits. SERP-1 is required for myxoma-virus virulence, and the purified protein has been shown to possess independent anti-inflammatory activity in animal models of restenosis and antigen-induced arthritis. As an inhibitor of serine proteinases, SERP-1 acts against tissue-type plasminogen activator, urokinase-type plasminogen activator, plasmin, thrombin and Factor Xa. In the present study, examination of SERP-1 glycosylation-site mutants showed that the N-linked glycosylation of Asn(172) was essential for SERP-1 secretion, whereas mutation of Asn(99) decreased secretion efficiency, indicating that N-linked glycosylation plays an essential role in the processing and trafficking of SERP-1. Furthermore, comparison of SERP-1 from wild-type myxoma virus and a virus containing a targeted disruption of the MST3N sialyltransferase locus demonstrated that SERP-1 is specifically modified by this myxoma-virus-encoded sialyltransferase, and is thus the first reported viral protein shown to by modified by a virally encoded glycosyltransferase. Sialylation of SERP-1 by the MST3N gene product creates a uniquely charged species of secreted SERP-1 that is distinct from SERP-1 produced from other eukaryotic expression systems, though this has no apparent effect upon the kinetics of in vitro proteinase inhibition. Rather, the role of viral sialylation of SERP-1 likely relates to masking antigenicity or targeting SERP-1 to specific sites of action in vivo.

Immunomodulation by viruses: the myxoma virus story.

Myxoma virus is a poxvirus pathogen of rabbits that has evolved to replicate successfully in the presence of an active immune response by an infected host. To accomplish this, the virus has developed a variety of strategies to avoid detection by or obstruct specific aspects of the antiviral response whose consolidated action is antagonistic to virus survival. We describe two distinct viral strategies carried out by viral proteins with which myxoma virus subverts the host immune response. The first strategy is the production of virus-encoded proteins known as viroceptors or virokines that mimic host receptors or cytokines. These seek to actively block extracellular immune signals required for effective virus clearance and produce a local environment in the infected tissue that is "virus friendly". The second strategy, carried out by intracellular viral proteins, seeks to retard the innate antiviral responses such as apoptosis, and hinder attempts by the infected cell to communicate with the cellular arm of the immune system. By studying these viral strategies of immune evasion, the myxoma system can provide insights into virus-host interactions and also provide new insights into the complex immune system.

Levels of medical support for United Nations peacekeeping operations.

It is important to standardize the classification of medical units in United Nations (U.N.) peacekeeping operations to ensure that they meet operational requirements and to facilitate planning and administration. It further ensures interoperability between medical facilities from different countries. The U.N. Department of Peacekeeping Operations has adopted a four-level medical support organization, with the classification level of a unit largely determined by its treatment capability and capacity. Planning and allocation of medical resources depend largely on the peacekeeping mandate, the type of peacekeeping operation, existing medical infrastructure, geographical factors, and assessed medical threats. A summary of medical units currently deployed in U.N. peacekeeping missions is presented. This should promote understanding of the U.N. medical support concept and assist national military organizations in the planning for such operations.

Functional comparisons among members of the poxvirus T1/35kDa family of soluble CC-chemokine inhibitor glycoproteins.

Many poxviruses express a 35-40-kDa secreted protein, termed "T1" (for leporipoxviruses) or "35kDa" (for orthopoxviruses), that binds CC-chemokines with high affinity but is unrelated to any known cellular proteins. Many previously identified poxvirus cytokine-binding proteins display strict species ligand-binding specificity. Because the T1 and 35kDa proteins share only 40% amino acid identity, we compared the abilities of purified myxoma virus-T1 (M-T1) and vaccinia virus (strain Lister)- and rabbitpox virus-35kDa proteins to inhibit human CC-chemokines in vitro. All three proteins were equally effective in preventing several human CC-chemokines from binding to target chemokine receptors and blocking subsequent intracellular calcium release. The inhibitory affinities were comparable (Ki = 0.07-1.02 nM). These proteins also displayed similar abilities to inhibit (IC50 = 6.3-10.5 nM) human macrophage inflammatory protein-1alpha-mediated chemotaxis of human monocytes. None of the viral proteins blocked interleukin-8-mediated calcium flux or chemotaxis of human neutrophils, confirming that the biological specificity of the T1/35kDa family is targeted inhibition of CC-chemokines. Despite the significant sequence divergence between the leporipoxvirus T1 and orthopoxvirus 35kDa proteins, our data suggest that their CC-chemokine binding and inhibitory properties appear to be species nonspecific and that the critical motifs most likely reside within the limited regions of conservation.

A behavioral analysis of eye protection use by soldiers.

One of the major problems faced by eye injury prevention programs in the military is the low compliance among individual soldiers with eye armor use. We use three different health behavioral models (the health belief model, the social learning theory, and the PRECEDE model) to analyze and explore the various factors involved in the use of eye armor. Some of the factors that appear to be important in affecting the behavior include environmental conditions (e.g., actual military deployment versus nondeployment activity), organizational attitude toward eye protection programs, community influence, individual knowledge and perception of eye injury, and belief in the efficacy of eye armor. An understanding of these factors can help influence the development of more effective strategies for eye injury prevention in the military.

Viral nucleotide changes in asymptomatic hepatitis B carriers undergoing interferon treatment.

BACKGROUND: Interferon might induce mutation in regions of hepatitis B virus DNA that encode for immunologic target of cytotoxic T lymphocytes. AIM: To investigate the short-term effect of steroid priming and interferon therapy on hepatitis B virus, we followed the nucleotide changes in the precore and core region of hepatitis B virus DNA in seven healthy asymptomatic carriers who underwent steroid priming followed by recombinant alpha interferon for 3 months. METHODS: Hepatitis B virus DNA from serial sera of the patients were polymerase chain reaction-amplified, and the precore and core region directly sequenced and analysed. RESULTS: Analysis revealed no serial changes in the hepatitis B virus nucleotide sequence in any of the patients. CONCLUSIONS: Steroid priming and short-term treatment with interferon in healthy asymptomatic patients does not select for hepatitis B virus with mutations in the precore and core region.