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V Anantharaman

Publications and source records attributed to V Anantharaman.

At least 19 recordsLinked to original sources
PubMed2005

Results of the first five years of the prehospital automatic external defibrillation project in Singapore in the "Utstein style".

In 1994, all emergency medical services (EMS) ambulance officers in Singapore were trained to perform pre-hospital defibrillation with semi-automated external defibrillators (AED). All non-traumatic cardiac arrest patients over 10 years old were included, excluding those who were obviously dead and children below 36 kg. The data were collected by the ambulance officers according to the Utstein guidelines. From 1 February 1994 to 31 January 1999; resuscitation was attempted in 968 non-trauma cardiac arrests. Fifteen percent of the cases were of non-cardiac origin. The overall survival rate was 40/968 (4.1%, 95% CI 2.9-5.6%). Of 968 patients, 22/136 (16.2%, 95% CI 10.4-23.5%), 18/622 (2.9%, 95% CI 1.7-4.5%) and 0/210 (0%, 95% CI 0-1.7%) survived in the EMS witnessed, bystander witnessed and un-witnessed groups, respectively (P < 0.001). Within the EMS witnessed group, those with an initial rhythm of VF/VT had a higher survival rate (30.6%) than those without VF/VT (4.1%). P < 0.001, OR = 10.3, 95% CI 2.9-36.9. Similarly, the VF/VT survival rate in the bystander witnessed group (4.5%) was higher than the non-VF/VT (1.0%) (P = 0.011, OR = 4.4, 95% CI 1.3-15.4). The survival rate of patients with bystander witnessed VF/VT arrest who received bystander CPR was 9.4% compared to 1.0% in those who did not (P = 0.037, OR = 4.4, 95% CI 1.01-20.1). Our survival rate of bystander witnessed VF/VT arrest is comparable to large metropolitan cities in the USA. The determinants of survival include EMS witnessed arrest and VF/VT arrest. Increased quantity and quality of bystander CPR rate may improve the outcome in bystander witnessed cardiac arrest.

Adolescent↗
PubMed2005

Performance of a population-based cardiac risk stratification tool in Asian patients with chest pain.

OBJECTIVES: Most contemporary cardiac risk stratification tools have been derived and validated in mixed-race populations. Their validity in single-race populations has not been tested. The authors sought to compare the performance of a risk stratification tool between a mixed-race U.S. patient population and an Asian patient population. METHODS: This study is an analysis of data from the Internet Tracking Registry for Acute Coronary Syndromes (i(*)trACS) registry of patients with chest pain presenting to the emergency departments of eight U.S. centers and one site in Singapore. The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) was computed for included patients, and its performance in predicting acute coronary syndrome (ACS) was compared between patients from the United States and Singapore. RESULTS: Of the 11,991 included patients, 1,120 experienced ACS. Although the ACI-TIPI demonstrated similar accuracy among groups (area under the curve, 0.729 [U.S.] vs. 0.719 [Singapore]; p = 0.5611), sensitivity and specificity were different when equal ACI-TIPI thresholds were considered. Recreating the logistic regression models used to create the ACI-TIPI showed similar results between the derived parameters and the parameters estimated for the U.S. group. In contrast, age older than 50 years (log-odds ratio [LOR], 0.107; 95% confidence interval [CI] = 0.518 to 0.713), male gender (LOR, 0.487; 95% CI = 0.149 to 1.122), and chest pain as a primary complaint (LOR, 0.237; 95% CI = 0.139 to 0.613) had little predictive power in patients from Singapore. CONCLUSIONS: Differences exist in presentation and factors associated with ACS among patients from the United States and Singapore that may affect the performance of risk stratification tools. These findings suggest that cardiac clinical decision rules need international validation.

Acute Disease↗
PubMed2004

The SHS2 module is a common structural theme in functionally diverse protein groups, like Rpb7p, FtsA, GyrI, and MTH1598/TM1083 superfamilies.

Using structural comparisons, we identified a novel domain with a simple fold in the bacterial cell division ATPase FtsA, the archaeo-eukaryotic RNA polymerase subunit Rpb7p, the GyrI superfamily, and the uncharacterized MTH1598/Tm1083-like proteins. The fold contains a core of 3 strands, forming a curved sheet, and a single helix in a strand-helix-strand-strand (SHS2) configuration. The SHS2 domain may exist either in single or duplicate copies within the same polypeptide. The single-copy versions of the domain in FtsA and Rbp7p are most closely related, and appear to mediate protein-protein interactions by means of strand 1, and the loop between strand 2 and strand 3 of the domain. We predict that the interactions between FtsA and its functional partners in bacterial cell division are likely to be similar to the interactions of Rbp7p in the archaeo-eukaryotic RNA polymerase complex. The dimeric versions typified by the GyrI superfamily appear to have been adapted for small-molecule binding. Sequence profiles searches helped us to identify several new versions of the GyrI superfamily, including a family of secreted forms that is found only in animals and the bacterial pathogen Leptospira. Through sequence-structure comparisons, we predict the positions that are likely to be important for ligand specificity in the GyrI superfamily. In the MTH1598/Tm1083-like proteins, a SHS2 domain is inserted into the loop between strand 1 and helix 1 of another SHS2 domain. This has resulted in a structure that has convergent similarities with the Hsp33 and green fluorescent protein folds. The sequence conservation pattern and its phyletic profile suggest that it might function as an enzyme in some conserved aspect of nucleic acid metabolism. Thus, the SHS2 domain is an example of a simple module that has been adapted to perform an entire spectrum of functions ranging from protein-protein interactions to small-molecule recognition and catalysis.

Amino Acid Sequence↗
PubMed2003

The need for drug and poison information--the Singapore physicians' perspective.

INTRODUCTION: There appears to be a significant prevalence of poisoning and adverse drug reactions in Singapore. However, the resources needed by physicians to assist them in the management of such cases are limited. This study examines the information resources currently utilised by medical professionals in assisting them in the management of poisonings and adverse drug reactions. The preferred features of an ideal Drug and Poison Information Centre in the local setting were also explored. METHOD: A questionnaire survey involving all practicing physicians in Singapore to find out the current information resources utilised for Drug and Poison Information and the need for enhanced resources and its preferred form was looked at. RESULTS: A total of 1,071 practicing physicians responded forming 24% of all physicians in Singapore as of December 1997. Of these, 636 (61.3%) were general practitioners and the rest specialists. The main sources of poison information were Drug Index of Malaysia and Singapore or DIMS (73.7%), standard textbooks (70.1%), fellow colleagues (44.6%) and pharmacists (41.0%). In the opinion of most (82.4%), one well run and efficient Drug and Poison Information Centre was adequate for the whole island. The majority (58.9%) preferred that experienced individuals who could be consulted upon in times of need man such a service. CONCLUSION: The study shows the need for enhanced drug and poison information resources. The local physician community also expects guidance and expert advice from a specialist. With this in mind, it is worthwhile examining in depth the issues surrounding poison and adverse drug reaction management and the need for readily accessible Drug and Poison Information resources in Singapore.

Adverse Drug Reaction Reporting Systems↗
PubMed2002

Calcium channel blockers as first line treatment for broad complex tachycardia with right bundle branch block: ingenuity or folly?

OBJECTIVE: To study the response of regular broad-complex tachycardia (BCT) demonstrating right bundle branch block (RBBB) to treatment in the Emergency department (ED). METHODS: Retrospective chart review of management of patients with BCT, RBBB without a history of ischaemic heart disease. A diagnosis of ventricular tachycardia (VT) was made if the ECG showed features such as atrioventricular dissociation, capture or fusion beats or if VT was demonstrated during electrophysiological studies (EPS). RESULTS: A total of 25 patients were eligible. Nineteen patients were given intravenous (IV) calcium channel blockers (either verapamil or diltiazem), as first line treatment. Of these, 18 converted to sinus rhythm and the other one patient subsequently converted with amiodarone. The remaining six patients were given IV adenosine (n=3), lignocaine (n=2) or amiodarone (n=1) as first line treatment but none of them were converted. Of these, four of them converted with IV calcium channel blockers eventually. Of the other two patients, who were both given lignocaine initially, one deteriorated haemodynamically with the use of verapamil and required synchronised cardioversion to convert. The other patient did not respond to amiodarone and synchronised cardioversion but was subsequently converted with verapamil. The difference between the success rate of calcium channel blockers and other anti-arrhythmics is statistically significant (P<0.01 by Fischer's exact method). Fourteen cases had diagnoses of VT, including the two patients given lignocaine. Five cases were found to have supraventricular tachycardia with aberrant conduction. Six cases did not have confirmed diagnoses. CONCLUSION: In patients presenting with BCT and RBBB but without underlying ischaemic heart disease, there is evidence to suggest that calcium channel blockers could effectively be used as the treatment of choice.

Adult↗
PubMed2002

Slow-infusion of calcium channel blockers in the emergency management of supraventricular tachycardia.

OBJECTIVE: To compare the efficacy of verapamil and diltiazem as slow infusions in terminating spontaneous supraventricular tachycardia (SVT) in the emergency department (ED). METHOD: Patients of at least 10 years of age who presented to our ED with regular narrow complex tachycardia not converted with a vagal manoeuvre with an ECG diagnosis of SVT were included. Those who were haemodynamically unstable were excluded. Patients were randomized to undergo either verapamil infusion at a rate of 1 mg/min to a maximum of 20 mg or diltiazem infusion at a rate of 2.5 mg/min to a maximum of 50 mg. RESULTS: Eighty-one patients were randomized to receive verapamil infusion and 80 were randomized to receive the diltiazem infusion. There is no difference in success rate between verapamil (98.8%) and diltiazem (96.3%) infusion. The dose of medication required to convert 25,50 and 75% of SVTs were 4.0,5.0 and 8.0 mg for the verapamil infusion and 10.0,12.5 and 17.5 mg for the diltiazem infusion. There was one complication in each group. CONCLUSION: Calcium channel blockers infusions were safe and efficacious in terminating spontaneous SVT. There was no difference between the success rates of verapamil and diltiazem infusions.

Calcium Channel Blockers↗
PubMed2002

Self perceived work related stress and the relation with salivary IgA and lysozyme among emergency department nurses.

AIMS: To assess and compare the self perceived work related stress among emergency department (ED) and general ward (GW) nurses, and to investigate its relation with salivary IgA and lysozyme. METHODS: One hundred and thirty two of 208 (63.5%) registered female ED and GW nurses participated in the study. A modified mental health professional stress scale (PSS) was used to measure self perceived stress. ELISA methods were used to determine the salivary IgA and lysozyme levels. RESULTS: On PSS, ED nurses had higher scores (mean 1.51) than GW nurses (1.30). The scores of PSS subscales such as organisational structure and processes (OS), lack of resources (RES), and conflict with other professionals (COF) were higher in ED than in GW nurses. ED nurses had lower secretion rates of IgA (geometric mean (GM) 49.1 micro g/min) and lysozyme (GM 20.0 micro g/min) than GW nurses (68.2 micro g/min, 30.5 micro g/min). Significant correlations were observed between PSS and log IgA and lysozyme secretion rates. OS, RES, and COF were correlated with log IgA and lysozyme levels. CONCLUSION: ED nurses, who reported a higher level of professional stress, showed significantly lower secretion rates of salivary IgA and lysozyme compared to GW nurses. Salivary IgA and lysozyme were inversely correlated with self perceived work related stress. As these salivary biomarkers are reflective of the mucosal immunity, results support the inverse relation between stress and mucosal immunity.

Adult↗
PubMed2002

Acute coronary syndrome--factors causing delayed presentation at the Emergency Department.

INTRODUCTION: The aim of the study was to identify factors that contributed to delays in presentation of patients with acute coronary syndrome (ACS) at the Emergency Department (ED). MATERIALS AND METHODS: The study population comprised patients presenting with the signs and symptoms of ACS at the ED of 5 government and restructured hospitals in Singapore from 1 April to 31 May 1999. These patients were interviewed with a structured questionnaire which explored patient demographic data, risk factors, prehospital symptomatology, timing of chest pain, patient response to chest pain and mode of transport to the hospital. RESULTS: Three hundred and two patients who made 307 visits were recruited. More than three-quarters of the patients presented with central or left-sided chest pain. Forty-seven per cent had breathlessness and 42% had sweating. The commonest day of presentation was Monday. It took patients a median time of 2.1 hours from their worst chest pain to arrive at the ED. Past history of diabetes mellitus was associated with a longer delay in presentation. Most of the delay was due to patients awaiting symptom resolution. Forty per cent came by emergency ambulances to hospital. CONCLUSION: Our findings identified various patient characteristics that contributed to delay in presentation to hospital which should be addressed in future education campaigns.

Adult↗
PubMed2002

Intravenous adrenaline or vasopressin in sudden cardiac arrest: a literature review.

INTRODUCTION: The chain of survival concept implies that provision of early access, early advanced care, including early intravenous drugs would improve survival in sudden cardiac arrest. Intravenous adrenaline (epinephrine) has been used as the drug of choice since 1906. What is the evidence for its effectiveness? Is vasopressin a better alternative? METHODS: We performed a systematic literature search in order to answer these questions. Evidence from the clinical trials that have been conducted on this subject was reviewed. RESULTS: Experimental evidence confirms the beneficial effect adrenaline has on coronary perfusion pressure. However, adrenaline has not been shown conclusively to improve survival in clinical trials. Extensive trials have also failed to show any benefit of high-dose adrenaline over standard doses. Vasopressin seems to be more effective than adrenaline in animal studies for treatment of cardiac arrest due to resistant ventricular fibrillation. However, it has yet to be proven to be superior to adrenaline in clinical trials. CONCLUSION: More research is needed into this area, especially randomised controlled trials studying the effectiveness of vasopressin. Meanwhile, in order to improve survival from sudden cardiac arrest, continuing effort should be made to achieve early initiation of cardiopulmonary resuscitation, early defibrillation and early advanced care.

Critical Care↗
PubMed2001

Peptide-N-glycanases and DNA repair proteins, Xp-C/Rad4, are, respectively, active and inactivated enzymes sharing a common transglutaminase fold.

Yeast RAD4, its human ortholog Xp-C and their orthologs in other eukaryotes are DNA repair proteins which participate in nucleotide excision repair through a ubiquitin-dependent process. However, no conserved globular domains that might have shed light on their origin or functions have been reported for these proteins. By using sequence profile analysis, we show that RAD4/Xp-C proteins contain the ancient transglutaminase fold and are specifically related to the recently characterized peptide-N-glycanases (PNGases) which remove glycans from glycoproteins during their degradation. The PNGases retain the catalytic triad that is typical of this fold and are predicted to have a reaction mechanism similar to that involved in transglutamination. In contrast, the RAD4/Xp-C proteins are predicted to be inactive and are likely to only possess the protein interaction function in DNA repair. These proteins also contain a long, low-complexity insert in the globular transglutaminase domain. The RAD4/Xp-C proteins, along with other inactive transglutaminase-fold proteins, represent a case of functional re-assignment of an ancient domain following the loss of the ancestral enzymatic activity.

Amidohydrolases↗
PubMed2001

Regulatory potential, phyletic distribution and evolution of ancient, intracellular small-molecule-binding domains.

Central cellular functions such as metabolism, solute transport and signal transduction are regulated, in part, via binding of small molecules by specialized domains. Using sensitive methods for sequence profile analysis and protein structure comparison, we exhaustively surveyed the protein sets from completely sequenced genomes for all occurrences of 21 intracellular small-molecule-binding domains (SMBDs) that are represented in at least two of the three major divisions of life (bacteria, archaea and eukaryotes). These included previously characterized domains such as PAS, GAF, ACT and ferredoxins, as well as three newly predicted SMBDs, namely the 4-vinyl reductase (4VR) domain, the NIFX domain and the 3-histidines (3H) domain. Although there are only a limited number of different superfamilies of these ancient SMBDs, they are present in numerous distinct proteins combined with various enzymatic, transport and signal-transducing domains. Most of the SMBDs show considerable evolutionary mobility and are involved in the generation of many lineage-specific domain architectures. Frequent re-invention of analogous architectures involving functionally related, but not homologous, domains was detected, such as, fusion of different SMBDs to several types of DNA-binding domains to form diverse transcription regulators in prokaryotes and eukaryotes. This is suggestive of similar selective forces affecting the diverse SMBDs and resulting in the formation of multidomain proteins that fit a limited number of functional stereotypes. Using the "guilt by association approach", the identification of SMBDs allowed prediction of functions and mode of regulation for a variety of previously uncharacterized proteins.

Amino Acid Sequence↗
PubMed2001

TRAM, a predicted RNA-binding domain, common to tRNA uracil methylation and adenine thiolation enzymes.

A previously undetected conserved domain is identified in two distinct classes of tRNA-modifying enzymes, namely uridine methylases of the TRM2 family and enzymes of the MiaB family that are involved in 2-methylthioadenine formation. This domain, for which the acronym TRAM is proposed after TRM2 and MiaB, is predicted to bind tRNA and deliver the RNA-modifying enzymatic domains to their targets. In addition to the two families of RNA-modifying enzymes, the TRAM domain is present in several other proteins associated with the translation machinery and in a family of small, uncharacterized archaeal proteins that are predicted to have a role in the regulation of tRNA modification or translation. Secondary structure prediction indicates that the TRAM domain adopts a simple beta-barrel fold. In addition, sequence analysis of the MiaB family enzymes showed that they share the predicted catalytic site with biotin and lipoate synthases and probably employ the same mechanism for sulfur insertion into their respective substrate.

Adenine↗
PubMed2001

Mass cardiopulmonary resuscitation 99--survey results of a multi-organisational effort in public education in cardiopulmonary resuscitation.

Mass cardiopulmonary resuscitation (CPR) 99 in Singapore was a large-scale multi-organisational effort to increase awareness and impart basic cardiac life support skills to the lay public. Mass CPR demonstrations followed by small group manikin practice with instructor guidance was conducted simultaneously in three centres, four times a day. The exercise enlisted 15 community organisations and received the support of 19 other organisations. Three hundred and ninety-eight manikins and 500 instructors ('I's) were mobilised to teach an audience of 6000 participants ('P's). Two surveys, for 'I's and 'P's were conducted with respondent rates of 65.8% and 50%, respectively. 73.6% of the P-respondents ('P-R's) indicated that they attended the event to increase their knowledge. 66.9% were willing to attend a more comprehensive CPR course. Concerns and perceptions in performing bystander CPR were assessed.

Advertising↗
PubMed2001

The CHASE domain: a predicted ligand-binding module in plant cytokinin receptors and other eukaryotic and bacterial receptors.

A novel, 200-230 amino acid extracellular domain was identified in the plant cytokinin receptor Cre1, in the receptor-histidine kinase DhkA and the adenylyl cyclase Acg from the slime mold Dictyostelium discoideum, and in a variety of other receptor-like proteins from bacteria and eukaryotes. The domain is predicted to bind diverse low molecular weight ligands, such as the cytokinin-like adenine derivatives or peptides, and mediate signal transduction through the respective receptors.

Adenylyl Cyclases↗
PubMed2001

Hospital and emergency ambulance link: using IT to enhance emergency pre-hospital care.

Emergency ambulances traditionally inform receiving hospitals of impending arrival of patients only in instances of load and go situations, which on average constitute less than 5% of ambulance runs. Information transmitted is usually sparse. For all other runs, information is made available only on arrival at the emergency department (ED). There have also been numerous limitations associated with voice transmissions.A comprehensive electronic ambulance case record was created as a pilot project in Singapore between three emergency ambulances and the busiest ED there. All information captured by the ambulance crew, including vital signs information and ECGs was entered or downloaded onto a ruggardised PC in the ambulance and this complete ambulance record was transmitted to the ED. Transmission was wireless via the public mobile data network. A 3-month analysis of this pilot run revealed the following. (1) It was possible to capture a complete ambulance case record electronically at a mean time of 94 s vs 7 min 7 s for the traditional written record. (2) Air transmission time for data was approximately 4 s unless ECG wave forms were also transmitted resulting in transmission times frequently exceeding 60 s. (3) At least 68% of data was transmissible in 75% of Hospital & Emergency Ambulance Link (HEAL) ambulances as opposed to only 25% in less than 5% of non-HEAL ambulances. (4) Paramedics' time in the ED decreased from 15 to 8 min as a result of HEAL. (5) The waiting time for critical care patients to be seen at the ED decreased from 35 to 17 min if brought by HEAL ambulances.(6) The HEAL system was able to effectively prompt paramedics in carrying out critical aspects of treatment in close to 100% of instances. (7) The pilot HEAL system was able to demonstrate a limited amount of automated audit of specific aspects of ambulance runs. Having demonstrated the feasibility of the HEAL system, it is a matter of time before enhanced features such as electronic data collection at patient site, voice activated data entry, transmission of data from site, automated ambulance audits and an enhanced level of professional care in the ambulances become common-place reality.

Ambulances↗
PubMed2000

Effects of Nucleoside Analogs on Native and Site-Directed Mutants of HTLV Type 1 Reverse Transcriptase.

A bacterial assay was developed for testing HTLV-1 reverse transcriptase sensitivity to common nucleoside analog inhibitors in an Escherichia coli strain characterized by a temperature sensitive PolI/RecA deletion phenotype. This genetic complementation assay exploits the ability of HTLV-1 reverse transcriptase to functionally replace these missing activities at nonpermissive temperatures. The four inhibitors tested, dideoxyinosine, dideoxyadenosine, deoxythymidine, and didehydrodeoxythymidine are well-known inhibitors of HIV reverse transcriptase. All except dideoxyadenosine showed a strong activity against HTLV-1 reverse transcriptase with IC(50); in the nanomolar range. Sequence alignments were used to identify amino acid residues in HTLV-1 reverse transcriptase, which correspond to those identified as important for drug-resistance in HIV reverse transcriptase. Mutations of some of these HTLV-1 residues altered the IC(50) for the inhibitors as expected, which suggests that these amino acids have a function in HTLV-1 reverse transcriptase similar to that of their homologs in HIV reverse transcriptase. Copyright 2000 Academic Press.

Journal Article↗