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1.
CJEM ; 26(3): 198-203, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38219263

ABSTRACT

BACKGROUND AND AIM: Emergency Department (ED) renal point-of-care ultrasound (PoCUS) in renal colic by accredited specialists has good prognostic value. This may not be generalizable to under-resourced EDs. We investigated PoCUS in renal colic in our ED with lesser training. METHODS: We performed a single-centre health records review of adult ED patients with renal colic and PoCUS. Patients were managed by a non-ED specialist/resident doctor with no POCUS accreditation in consultation with an attending. These doctors attended a 3.5-h training session conducted by accredited attendings to examine hydronephrosis. They needed to verify their PoCUS findings with an attending during the first two weeks of their six-month posting before performing it independently. The primary outcome was 30-day urological procedures in hydronephrotic vs. non-hydronephrotic groups. Secondary outcomes were the distribution of primary outcome with grades of hydronephrosis, 30-day ED nephrolithiasis-related reattendances in hydronephrotic vs. non-hydronephrotic groups and its distribution with grades of hydronephrosis. We compared outcomes using Fisher's exact test. We also reported crude odds ratio (COR) and 95% CI of primary outcome between hydronephrotic vs. non-hydronephrotic groups. p values ≤ 0.05 were significant. RESULTS: We recruited 651 patients; 160 (24.6%) without and 491 (75.4%) with hydronephrosis. Rates of grades of hydronephrosis were: mild (76.6%), moderate (13.8%), severe (1.2%) and undifferentiated (8.4%). There was a difference in 30-day urological procedures (rates [95% CI]) in hydronephrotic vs. non-hydronephrotic groups, 11.2 [8.7-14.0]% vs. 2.5 [1.0-6.3]%; p < 0.001; COR (95% CI) 4.9 (1.8-13.8); p = 0.002. Increasing 30-day urological procedural rates were associated with increasing grade of hydronephrosis [no: 2.5%, mild: 7.7%, moderate: 23.5%, severe: 67.0% and undifferentiated: 14.6%; p < 0.001]. No differences occurred in other secondary outcomes. CONCLUSIONS: Renal PoCUS could be performed by non-ED specialist/resident doctors to identify patients without hydronephrosis who rarely required urological intervention. Hydronephrotic patients could benefit from further risk stratification.


ABSTRAIT: CONTEXTE ET OBJECTIF: L'échographie rénale au point de soin (PoCUS) dans les coliques rénales par des spécialistes agréés a une bonne valeur pronostique. Cela peut ne pas être généralisable aux SU sous-financés. Nous avons étudié PoCUS dans les coliques rénales dans notre DE avec une formation moindre. MéTHODES: Nous avons effectué un examen des dossiers médicaux d'un seul centre des patients adultes atteints de coliques rénales et de PoCUS. Les patients étaient pris en charge par un médecin résident/spécialiste non-membre de la DG sans accréditation POCUS en consultation avec un médecin traitant. Ces médecins ont assisté à une séance de formation de 3,5 heures menée par des titulaires accrédités pour examiner l'hydronéphrose. Ils devaient vérifier leurs résultats PoCUS auprès d'un assistant pendant les deux premières semaines de leur affectation de six mois avant de l'effectuer de manière indépendante. Le critère de jugement principal était des procédures urologiques de 30 jours dans les groupes hydronéphrotiques vs non-hydronephrotiques. Les critères de jugement secondaires étaient la distribution du critère de jugement primaire avec les grades d'hydronéphrose, les reattendances liées à la néphrose ED de 30 jours dans les groupes hydronéphrotiques vs non hydronéphrotiques et sa distribution avec les grades d'hydronéphrose. Nous avons comparé les résultats en utilisant le test exact de Fisher. Nous avons également signalé un rapport de cotes brut (RC) et un IC à 95 % du critère de jugement principal entre les groupes hydronéphrotiques et non hydronéphrotiques. Les valeurs de P 0,05 étaient significatives. RéSULTATS: Nous avons recruté 651 patients; 160 (24,6%) sans et 491 (75,4%) avec hydronéphrose. Les taux d'hydronéphrose étaient les suivants : légère (76,6 %), modérée (13,8 %), sévère (1,2 %) et indifférenciée (8,4 %). Il y avait une différence dans les interventions urologiques de 30 jours (taux [IC à 95 %]) dans les groupes hydronéphrotiques par rapport aux groupes non-hydronephrotiques, 11,2 [8,7-14,0] % contre 2,5 [1,0-6,3]%; p < 0,001; RCC (IC à 95 %) 4,9 (1,8-13,8); p = 0,002. L'augmentation des taux de procédures urologiques de 30 jours était associée à l'augmentation du grade d'hydronéphrose [non : 2,5%, léger : 7,7%, modéré : 23,5%, sévère : 67,0% et indifférencié : 14,6%; p < 0,001]. Aucune différence n'est survenue dans les autres critères de jugement secondaires. CONCLUSIONS: La PoCUS rénale pourrait être réalisée par des médecins non spécialistes/résidents de la D pour identifier les patients sans hydronéphrose qui ont rarement nécessité une intervention urologique. Les patients hydronéphrotiques pourraient bénéficier d'une meilleure stratification des risques.


Subject(s)
Hydronephrosis , Renal Colic , Adult , Humans , Renal Colic/diagnostic imaging , Point-of-Care Systems , Tomography, X-Ray Computed , Hydronephrosis/diagnostic imaging , Ultrasonography/methods , Emergency Service, Hospital
2.
Med J Malaysia ; 77(4): 454-461, 2022 07.
Article in English | MEDLINE | ID: mdl-35902935

ABSTRACT

INTRODUCTION: Coronavirus disease 2019 (COVID-19) variants pose unique challenges with inevitable premature death when cases of severe disease exponentially rise in a healthcare system. It is imperative that palliative care is provided with a proactive approach to symptom recognition, assessment, management and treatment escalation to ensure comfort throughout the course of this illness. OBJECTIVES: To evaluate the characteristics, symptom burden, palliative care management and outcomes of COVID-19 patients referred to a palliative care unit (PCU) in a single tertiary hospital. Clinical outcomes specifically observed the management of agitation in these patients based on their Richmond Agitation and Sedation Scale (RASS) scores. METHODS: A retrospective observational study was conducted in a tertiary hospital by reviewing electronic medical records and extracting data from 1st June 2021to 31st July 2021 of all COVID-19 patients referred to the PCU. RESULTS: A cohort of 154 (75 males, 79 females) COVID-19 patients was referred to the PCU with a mean age of 67 (20- 95) years. The median number of days of COVID-19 illness before referral was 7(4-11), with 79.3% of patients being in categories 4 and 5. The median duration of the PCU involvement was 4(1-24) days; 74% of families were engaged in virtual platform communication. The most prevalent symptoms were dyspnoea (73.4%) and agitation (41.6%). Common medications used were opioids, antipsychotics and benzodiazepines. Among agitated patients, none had RASS scores above +2 in the last encounter. Palliative care doctors in the team reported complete effectiveness in patient's symptom control in 74% of patients. CONCLUSIONS: A hallmark of severe COVID-19 is rapid deterioration, which calls for proactive assessment and urgent palliation. Breathlessness and agitation are priority symptoms to address. Among agitated patients, benzodiazepines and antipsychotics are highly effective in addressing agitation and reducing RASS scores. Communication with families using virtual platforms is effective in providing a supportive presence and closure when face-to-face communication is not possible.


Subject(s)
COVID-19 , Palliative Care , Aged , Benzodiazepines , COVID-19/therapy , Female , Humans , Male , Referral and Consultation , Tertiary Care Centers
3.
Transplant Proc ; 49(8): 1797-1805, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28923628

ABSTRACT

BACKGROUND: Liver transplant (LT) patients with significant coronary artery disease (CAD) have poorer outcomes. Pre-LT coronary angiography (CA) is associated with significant complications in cirrhotic patients. METHODS: This study aimed to identify predictors of abnormal CA in pre-LT cardiac assessment and to develop a predictive model to reduce unnecessary CA. From January 2006 to June 2013, 122 patients underwent CA based on the current institutional protocol. RESULTS: Forty-one (33.6%) patients had abnormal CA. Univariate analysis showed age ≥65 years (P = .001), cryptogenic cirrhosis (P = .046), cardiac comorbidities (P = .027), ischemic heart disease (IHD; P = .002), left ventricular hypertrophy (LVH; P = .004), hypertension (P = .002), diabetes mellitus (P = .017), dyslipidemia (P < .001), metabolic syndrome (P = .003), ≥2 CAD risk factors (P = .001), and high Framingham risk score (hard CAD risk, P = .018; cardiovascular disease: lipids, P = .002; body mass index, P < .001) to be significant predictors of abnormal CA. A predictive model was developed with the use of multivariable logistic regression and included diabetes, dyslipidemia, IHD, age ≥65 years, and LVH, achieving a specificity of 55.1% and sensitivity of 90.0%. This would reduce unnecessary CA by up to one-half in our study population (from 81 to 35) while maintaining a false negative rate of only 8.5%. CONCLUSIONS: Diabetes, dyslipidemia, IHD, age ≥65 years, and LVH appear to be predictors of abnormal CA in pre-LT patients. Our predictive model may help to better select patients for CA, although further validation is required.


Subject(s)
Coronary Angiography/statistics & numerical data , Coronary Artery Disease/diagnosis , End Stage Liver Disease/complications , Liver Transplantation , Adult , Aged , Asian People , Cardiovascular Diseases , Comorbidity , Coronary Artery Disease/epidemiology , Coronary Artery Disease/etiology , Diabetes Complications , Dyslipidemias/complications , Female , Humans , Hypertension/complications , Hypertrophy, Left Ventricular/complications , Liver Cirrhosis/complications , Liver Cirrhosis/congenital , Logistic Models , Male , Middle Aged , Myocardial Ischemia/complications , Predictive Value of Tests , Risk Factors , Sensitivity and Specificity , Transplants , Young Adult
4.
Singapore Med J ; 52(12): 914-8; quiz 919, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22159936

ABSTRACT

The Ministry of Health (MOH) has published clinical practice guidelines on Bipolar Disorder to provide doctors and patients in Singapore with evidence-based guidance on the management of bipolar disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Bipolar Disorder, 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/content/moh_web/home/Publications/guidelines/clinical_practiceguidelines/2011/bipolar_disorder.html. 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.


Subject(s)
Bipolar Disorder , Adolescent , Adult , Child , Humans , Bipolar Disorder/diagnosis , Bipolar Disorder/therapy , Evidence-Based Medicine , Psychiatry/methods , Psychiatry/standards , Singapore
6.
Singapore Med J ; 52(1): e12-4, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21298228

ABSTRACT

Intravenous (IV) metoclopramide is a frequently prescribed medication in the emergency department (ED). Extrapyramidal side effects like tardive dyskinesia are known to develop with chronic use of metoclopramide, while acute akathisia is a lesser known side effect following IV administration. Akathisia is characterised by a sensation of restlessness and distress, as well as constant, non-purposeful limb movement. It can present as a diagnostic challenge, cause distress and hinder the management of the primary condition of the patient in the ED. However, akathisia can be readily reversible, with a successful patient outcome if promptly diagnosed. We report a case of acute akathisia in a young female patient after IV bolus metoclopramide was administered to treat her gastroenteritis in our ED. We highlight the diagnostic process, the difficulties in the management of the primary condition resulting from her akathisia and its successful management using IV diphenhydramine and midazolam.


Subject(s)
Akathisia, Drug-Induced/diagnosis , Infusions, Intravenous/adverse effects , Metoclopramide/administration & dosage , Metoclopramide/adverse effects , Abdominal Pain , Adult , Diphenhydramine/pharmacology , Emergency Service, Hospital , Female , Gastroenteritis/drug therapy , Humans , Hypnotics and Sedatives/pharmacology , Midazolam/pharmacology , Psychomotor Agitation , Treatment Outcome
7.
Emerg Med J ; 28(1): 18-24, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20943834

ABSTRACT

BACKGROUND: The authors' emergency department (ED) served as Singapore's screening centre for influenza H1N1 cases. The aims of the study were to describe their screening experience and to compare clinical and laboratory features of H1N1 versus seasonal flu cases. METHODOLOGY: The authors conducted a prospective observational study on consecutive patients aged 16 years and above presenting to a busy, urban ED for H1N1 screening over 50 days. Clinical, laboratory, radiological and PCR data were collected from the hospital electronic databases. Primary outcomes were proportions of confirmed H1N1 cases and their distribution of clinical, laboratory and radiological features. Secondary outcomes were comparison of clinical and laboratory features of H1N1 versus seasonal flu cases. Data were analysed using descriptive statistics and univariate analysis was used to compare factors between the two groups. A p value <0.05 was considered statistically significant. RESULTS: 1205 patients were screened. 31 (2.6%) and 133 (11%) of them had H1N1 and seasonal flu infections, respectively. The two groups had similar symptoms. There were six clinical and two laboratory features with statistically significant differences between H1N1 and seasonal flu cases. Clinical factors were travel or contact history, median age, respiratory rate, diastolic blood pressure and length of hospital stay. Laboratory factors were median platelet and lymphocyte counts. CONCLUSIONS: The authors report their experience as the nation's H1N1 screening centre. They identified factors that were different between H1N1 and seasonal flu cases. Future research is needed to elucidate if and how this information can be used as a screening tool for H1N1.


Subject(s)
Disease Outbreaks/prevention & control , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Mass Screening/methods , Adolescent , Adult , Age Distribution , Cohort Studies , Early Diagnosis , Emergency Service, Hospital , Female , Humans , Male , Middle Aged , Prevalence , Primary Prevention/organization & administration , Prospective Studies , Risk Assessment , Sex Distribution , Singapore/epidemiology , Survival Rate , Time Factors , Young Adult
8.
Singapore Med J ; 50(9): 881-4, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19787176

ABSTRACT

INTRODUCTION: In Singapore, a significant proportion of patients receive specialist dermatological services via referrals from points of primary care, such as polyclinics and emergency departments (ED). The study hospital, Tan Tock Seng Hospital, is an acute care general hospital with a large catchment area, and has the busiest ED in Singapore. The aim of this paper was to describe the types of dermatological conditions presented at the ED in the year 2007. This information is useful for the future education of junior doctors working in the department, as well as for the allocation of future resources in the treatment of the more common conditions. METHODS: The ED patient database was searched for all dermatological conditions by ICD-9 code and by keywords in the diagnosis description. The two lists were merged and duplications were eliminated. The consultation notes of the patients were reviewed in cases where the diagnosis was ambiguous. Patient demographics were then filtered and analysed. RESULTS: A total of 4,061 patients were seen in the ED with a primary dermatological complaint, out of a total of 157,527 attendances in 2007. The commonest conditions seen were chickenpox and herpes zoster (20.8 percent). Dermatitis/eczema (11.6 percent) and urticaria (11.4 percent), nail conditions including trauma and infections (10.2 percent) and drug rashes (9.7 percent) were also common. Venereal diseases (1 percent) were uncommonly seen in the ED. Interestingly, men (65.3 percent) were seen in the ED for dermatological conditions twice as often as women (34.7 percent). CONCLUSION: The recognition and management of the common conditions should be core modules in the training of doctors and nurses.


Subject(s)
Dermatology/methods , Emergency Service, Hospital/statistics & numerical data , Skin Diseases/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Dermatitis/epidemiology , Emergency Service, Hospital/trends , Exanthema/epidemiology , Female , Humans , Infant , Male , Medical Records , Middle Aged , Nail Diseases/epidemiology , Registries , Sex Factors , Singapore , Skin Diseases/epidemiology , Urticaria/epidemiology
9.
Singapore Med J ; 50(9): 885-8, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19787177

ABSTRACT

INTRODUCTION: While non-contrast computed tomography (CT) of the brain can be used to rapidly identify patients with altered mental status (AMS) in the emergency department (ED), with an acute intracranial bleed or infarct, a wide variation in its use exists. The aim of this pilot study was to identify the clinical predictors of an abnormal CT result in ED patients with AMS. METHODS: We conducted a retrospective study of patients aged 15 years and older presenting with undifferentiated AMS in a busy urban ED over one year. Data collected included demographical, clinical, laboratory and radiological features. The primary outcome of interest was the presence of an abnormal CT result defined as an acute infarct or intracranial bleed. Secondary outcomes were clinical predictors of an abnormal CT result. The data was analysed using descriptive statistics. Logistic regression was used to identify clinical predictors of an abnormal CT result. Odds ratios (ORs) were reported with 95 percent confidence intervals (CIs). RESULTS: 578 patients were recruited, of which 284 (49.1 percent) were males. 327 (56.6 percent) patients underwent CT of the brain. 128 scans (39.1 percent) were abnormal. Logistic regression revealed seven clinical features that were associated with an abnormal CT result. They were mean age greater than or equal to 73 years (OR 1.03; 95 percent CI 1.015-1.045), drowsiness or unresponsiveness (OR 1.73; 95 percent CI 0.17-17.72), previous cerebrovascular accident (OR 2.03; 95 percent CI 0.82-5.02), previous epilepsy (OR 1.63; 95 percent CI 0.63-4.19), tachycardia [greater than 120/min] (OR 1.16; 95 percent CI 0.38-3.54), bradycardia [less than 60/min] (OR 1.35; 95 percent CI 0.19-9.59) and exposure to drugs (OR 1.90; 95 percent CI 0.58-6.26). CONCLUSION: We identified seven clinical predictors of an abnormal CT result in AMS patients. Future research in prospective studies is needed to validate these findings.


Subject(s)
Consciousness Disorders/pathology , Consciousness Disorders/physiopathology , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Consciousness Disorders/diagnosis , Emergency Medicine/methods , Emergency Service, Hospital , Female , Humans , Intracranial Hemorrhages/diagnosis , Male , Middle Aged , Pilot Projects , Retrospective Studies
10.
Avian Pathol ; 33(5): 470-6, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15545026

ABSTRACT

The aim of this work was the selection and comparison of representative infectious bursal disease virus (IBDV) strains. Nine strains of IBDV, isolated at different times and from different geographic regions of Europe and China, were characterized. Batches of all strains were prepared following standardized protocols and checked for the absence of contaminating viruses. Criteria used for their characterization were: (i) the nucleotide sequence of the VP2 variable region, (ii) binding to a panel of neutralizing monoclonal antibodies in antigen capture enzyme-linked immunosorbent assays, and (iii) virulence in specific pathogen free chickens after infection with a standardized number of median embryo infective doses. Based on the first two criteria, two of nine strains were classified as classical virulent (cv) IBDV (F52/70, Cu-1wt), and five as very virulent (vv) IBDV (849VB, 96108, HK46, GX, Harbin). Remarkably, although a clear-cut difference was demonstrable between European cvIBDV (F52/70 and Cu-1wt) and vvIBDV (849VB and 96108) strains, there was a continuum in the pathogenicity of Chinese vvIBDVs. Our results indicate the probable existence of differences in virulence within IBDV lineages determined on the basis of antigenic typing using monoclonal antibodies and the alignment of the VP2 sequences. This indicates limitations in the analysis of IBDV pathotypes based on the VP2 variable region and emphasizes that these criteria may not be sufficient for the classification of IBDV strains.


Subject(s)
Antibodies, Monoclonal/metabolism , Infectious bursal disease virus/genetics , Infectious bursal disease virus/metabolism , Infectious bursal disease virus/pathogenicity , Viral Structural Proteins/genetics , Amino Acid Sequence , Animals , Base Sequence , Chickens/virology , China , Cluster Analysis , DNA Primers , Enzyme-Linked Immunosorbent Assay , Europe , Molecular Sequence Data , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Sequence Analysis, DNA , Species Specificity , Specific Pathogen-Free Organisms , Virulence
11.
Ann Acad Med Singap ; 31(4): 487-92, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12161885

ABSTRACT

INTRODUCTION: A preliminary one-year review of total parenteral nutrition (TPN) in the adult surgical intensive care unit (SICU) in view of its complications, cost and lack of consistent benefits in the critically ill. MATERIALS AND METHODS: All the case records of patients receiving TPN in the SICU starting from first January to end December 1998 were studied. RESULTS: Fifty patients received TPN during the study period. Four case records were unavailable. The indications for starting TPN were comparable with those set up by the Stanford University Hospital. Sepsis with gastrointestinal failure at 30.5% [95% CI, 17.7% to 45.8%] was one of the major indicators for TPN use and also the biggest contributor to mortality (50%) [95% CI, 35% to 65%]. Hyperglycaemia and line sepsis increased with duration of TPN use. Pneumonia, bacteraemia and wound infection peaked by the second week. Patients receiving TPN for inadequate and delayed enteral feeding fared better with 45.8% survival [95% CI, 30.9% to 61%]. None of the patients with polytrauma or malignancy cachexia died. 52.2% [95% CI, 37% to 67.1%] survived to be discharged from hospital. Caloric requirements were calculated using Harris-Benedect's equation and estimated using 30 to 35 kcal/kg/day. 64.3% were overfed and 50% received excessive non-protein calorie-to-nitrogen ratio. Ninety-eight per cent and 81% received less than the recommended amino-acid and glucose, respectively. Fifty-eight per cent received adequate lipids. CONCLUSION: This audit highlights the shortcomings in TPN prescription and characteristics of the attendant complications. Efforts must be directed towards encouraging uniformity and level of practice standards.


Subject(s)
Critical Care/statistics & numerical data , Critical Illness/therapy , Medical Audit/statistics & numerical data , Outcome Assessment, Health Care/statistics & numerical data , Parenteral Nutrition, Total/statistics & numerical data , Adult , Aged , Aged, 80 and over , Critical Care/economics , Critical Illness/economics , Female , Humans , Length of Stay/economics , Length of Stay/statistics & numerical data , Male , Middle Aged , Outcome Assessment, Health Care/economics , Parenteral Nutrition, Total/adverse effects , Parenteral Nutrition, Total/economics , Patient Selection , Severity of Illness Index , Time Factors
12.
Appl Microbiol Biotechnol ; 59(2-3): 190-7, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12111145

ABSTRACT

A novel phytase gene ( phyL) was cloned from Bacillus licheniformis by multiple steps of degenerate and inverse PCR. The coding region of the phyL gene was 1,146 bp in size and a promoter region of approximately 300 bp was identified at the upstream sequence. This gene, together with a phytase gene ( 168phyA) identified in the B. subtilis strain 168 genome by a homology search, was cloned and over-expressed in B. subtilis using a phi105MU331 prophage vector system. Up to 35 units of phytase/ml were secreted into the culture media; and mature enzymes of around 44-47 kDa were purified for characterization. Both phytases exhibited broad temperature and pH optima and showed high thermostability. Of the two, the phytase encoded by phyL exhibited higher thermostability, even at a lower calcium concentration, as it was able to recover 80% of its original activity after denaturation at 95 degrees C for 10 min. With their neutral pH optima and good temperature stabilities, these Bacillus phytases are good candidates for animal feed applications and transgenic studies.


Subject(s)
6-Phytase/genetics , Bacillus subtilis/enzymology , Bacillus/enzymology , 6-Phytase/chemistry , 6-Phytase/metabolism , Amino Acid Sequence , Base Sequence , Cloning, Molecular , Enzyme Stability , Hydrogen-Ion Concentration , Molecular Sequence Data
14.
Immunol Rev ; 180: 65-77, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11414365

ABSTRACT

Human gC1q-R (p33, p32, C1qBP, TAP) is a ubiquitously expressed, multiligand-binding, multicompartmental cellular protein involved in various ligand-mediated cellular responses. Although expressed on the surface of cells, an intriguing feature of the membrane-associated form of gC1q-R is that its translated amino acid sequence does not predict the presence of either a sequence motif compatible with a transmembrane segment or a consensus site for a glycosylphosphatidylinositol anchor. Moreover, the N-terminal sequence of the pre-pro-protein gC1q-R contains a motif that targets the molecule to the mitochondria and as such was deemed unlikely to be expressed on the surface. However, several lines of experimental evidence clearly show that gC1q-R is present in all compartments of the cell, including the extracellular cell surface. First, surface labeling of B lymphocytes with the membrane-impermeable reagent sulfosuccinimidyl 6-(biotinamido)hexanoate shows specific biotin incorporation into the surface-expressed but not the intracellular form of gC1q-R. Second, FACS and confocal laser scanning microscopic analyses using anti-gC1q-R IgG mAb 60.11 or 74.5.2, and the fluorophore Alexa 488-conjugated F(ab')2 goat anti-mouse IgG as a probe, demonstrated specific staining of Raji cells (>95% viable). Three-dimensional analyses of the same cells by confocal microscopy showed staining distribution that was consistent with surface expression. Third, endothelial gC1q-R, which is associated with the urokinase plasminogen activator receptor, and cytokeratin 1 bind 125I-high molecular weight kininogen in a specific manner, and the binding is inhibited dose-dependently by mAb 74.5.2 recognizing gC1q-R residues 204-218. Fourth, native gC1q-R purified from Raji cell membranes but not intracellular gC1q-R is glycosylated, as evidenced by a positive periodic acid Schiff stain as well as sensitivity to digestion with endoglycosidase H and F. Finally, cross-linking experiments using C1q as a ligand indicate that both cC1q-R and gC1q-R are co-immunoprecipitated with anti-C1q. Taken together, the evidence accumulated to date supports the concept that in addition to its intracellular localization, gC1q-R is expressed on the cell surface and can serve as a binding site for plasma and microbial proteins, but also challenges the existing paradigm that mitochondrial proteins never leave their designated compartment. It is therefore proposed that gC1q-R belongs to a growing list of a class of proteins initially targeted to the mitochondria but then exported to different compartments of the cell through specific mechanisms which have yet to be identified. The designation 'multifunctional and multicompartmental cellular proteins' is proposed for this class of proteins.


Subject(s)
Hyaluronan Receptors , Infections/metabolism , Inflammation/metabolism , Membrane Glycoproteins , Receptors, Complement/physiology , Amino Acid Motifs , Animals , Bacterial Proteins , Blood Platelets/metabolism , Blood Proteins/metabolism , Carrier Proteins , Cell Compartmentation , Cell Membrane/metabolism , Chemotaxis , Chromosomes, Human, Pair 17/genetics , Complement C1q/metabolism , Flow Cytometry , Gene Expression Regulation , Genes , Humans , Kininogen, High-Molecular-Weight/metabolism , Ligands , Lymphocyte Activation , Membrane Proteins/metabolism , Mice , Microscopy, Confocal , Mitochondria/metabolism , Mitochondrial Proteins , Neoplasm Proteins/physiology , Phagocytosis , Rats , Receptors, Complement/chemistry , Receptors, Complement/genetics , Receptors, Complement/immunology , Signal Transduction , Staphylococcal Protein A/metabolism , Structure-Activity Relationship , Subcellular Fractions/metabolism , Tumor Cells, Cultured , Viral Proteins/metabolism , Vitronectin/metabolism
15.
Avian Dis ; 45(2): 389-99, 2001.
Article in English | MEDLINE | ID: mdl-11417818

ABSTRACT

The in vitro and in vivo effects of chicken interferon alpha on infectious bursal disease virus (IBDV) infection were investigated in this study. A cDNA of interferon alpha was first cloned from a Chinese strain chicken Shiqi by reverse transcription-polymerase chain reaction. The deduced amino acid sequence has one amino acid substitution with chicken interferon alpha 1 at residue 65 (N to S) and two amino acid substitutions with chicken interferon alpha 2 at residues 50 (N to S) and 58 (P to L), respectively. A prokaryotic expression system was employed to produce a large quantity of recombinant protein. Recombinant interferon was purified in a one-step process, and an optimal refolding process was devised. About 51% recombinant protein from inclusion bodies was refolded, and the final yield of the recombinant interferon reached 24.66 mg/liter culture. The recombinant interferon suppressed IBDV plaque formation in a dose-dependent manner and ameliorated IBDV and Newcastle disease virus infection in both specific-pathogen-free (SPF) and commercial chickens. The antiviral effect of interferon alpha is more significant in commercial chickens than in SPF chickens, and the route of administration affects the efficacy of interferon therapy. This is the first reported study of the effects of interferon alpha on IBDV infection.


Subject(s)
Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Birnaviridae Infections/veterinary , Chickens , Interferon Type I/therapeutic use , Newcastle Disease/drug therapy , Poultry Diseases/drug therapy , Amino Acid Sequence , Animals , Antiviral Agents/chemistry , Antiviral Agents/immunology , Base Sequence , Birnaviridae Infections/drug therapy , DNA, Complementary/analysis , Dose-Response Relationship, Drug , Drug Administration Routes/veterinary , Infectious bursal disease virus/immunology , Interferon Type I/chemistry , Interferon Type I/genetics , Interferon Type I/immunology , Molecular Sequence Data , Newcastle disease virus/immunology , Poultry Diseases/virology , Recombinant Proteins , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Specific Pathogen-Free Organisms , Treatment Outcome
16.
Avian Dis ; 45(2): 504-11, 2001.
Article in English | MEDLINE | ID: mdl-11417836

ABSTRACT

A biotin-streptavidin system was established to directly visualize infectious bursal disease virus (IBDV)-binding cells in cell culture or in fresh tissues. The cells or tissue sections were first incubated with a biotinylated, purified IBDV strain GZ911 and then with a streptavidin-beta-galactosidase conjugate. In the presence of the enzyme substrate X-gal, IBDV-binding cells were labeled in blue color. By applying this method to frozen tissue sections, virus-binding sites were localized in situ in the bursa, spleen, and kidney tissue sections, whereas no positive cells were detected in the thymus tissue sections. Chicken embryo fibroblasts, Vero cells, MOP-8 cells, 293-EBNA cells, PANC-1 cells, and HuTu 80 cells were found to bind to the virus. However, the binding of the virus to MDA-MB-231 cells and SVG p12 cells was undetectable. This method can be employed for the expressional cloning of IBDV receptor and can be applied to studies on other avian viruses.


Subject(s)
Bacterial Proteins , Biotin/analogs & derivatives , Infectious bursal disease virus/isolation & purification , Infectious bursal disease virus/physiology , Viral Proteins/physiology , Animals , Binding, Competitive/physiology , Biotinylation , Bursa of Fabricius/virology , Cell Line , Cells, Cultured , Chick Embryo , Chickens , Culture Techniques/veterinary , Fibroblasts , Humans , Kidney/virology , Spleen/virology , Thymus Gland/virology
17.
J Biol Chem ; 276(20): 17069-75, 2001 May 18.
Article in English | MEDLINE | ID: mdl-11278463

ABSTRACT

gC1qR is an ubiquitously expressed cell protein that interacts with the globular heads of C1q (gC1q) and many other ligands. In this study, the 7.8-kilobase pair (kb) human gC1qR/p32 (C1qBP) gene was cloned and found to consist of 6 exons and 5 introns. Analysis of a 1.3-kb DNA fragment at the 5'-flanking region of this gene revealed the presence of multiple TATA, CCAAT, and Sp1 binding sites. Luciferase reporter assays performed in different human cell lines demonstrated that the reporter gene was ubiquitously driven by this 1.3-kb fragment. Subsequent 5' and 3' deletion of this fragment confined promoter elements to within 400 base pairs (bp) upstream of the translational start site. Because the removal of the 8-bp consensus TATATATA at -399 to -406 and CCAAT at -410 to -414 did not significantly affect the transcription efficiency of the promoter, GC-rich sequences between this TATA box and the translation start site may be very important for the promoter activity of the C1qBP gene. One of seven GC-rich sequences in this region binds specifically to PANC-1 nuclear extracts, and the transcription factor Sp1 was shown to bind to this GC-rich sequence by the supershift assay. Primer extension analysis mapped three major transcription start regions. The farthest transcription start site is 49 bp upstream of the ATG translation initiation codon and is in close proximity of the specific SP1 binding site.


Subject(s)
Hyaluronan Receptors , Membrane Glycoproteins , Promoter Regions, Genetic , Receptors, Complement/genetics , 3' Untranslated Regions/genetics , 5' Untranslated Regions/genetics , Base Sequence , Carrier Proteins , Cell Line , Complement C1q/metabolism , Consensus Sequence , Exons , Genomic Library , Humans , Introns , Mitochondrial Proteins , Molecular Sequence Data , Protein Biosynthesis , Receptors, Complement/chemistry , Receptors, Complement/metabolism , Recombinant Proteins/metabolism , Restriction Mapping , Sequence Deletion , TATA Box , Transfection
18.
Singapore Med J ; Suppl 1: 43-5, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11811602

ABSTRACT

Keeping the airway patent and protected is the crucial first step in resuscitation of collapsed patients. The patency of the airway can be maintained by head tilt, chin lift and jaw thrust, with or without the assistance of airway adjunct, for example oropharyngeal or nasopharyngeal airways. Before securing definitive airway by endotracheal intubation, the degree of difficulty for intubation can be predicted using Mallampati, Cormack and Lehane classification. Laryngeal mask airway may have a role in resuscitation. A comprehensive training program must be in place to improve the success rate of the laryngeal mask airway insertion and reduce the complication rate associated with the placement of this device. In order to ensure survival of collapsed patients, all medical and nursing staff must know when and how to manage the airways. "Do Not Resuscitate" orders should be written for terminally ill patients to reduce futile resuscitation.


Subject(s)
Cardiopulmonary Resuscitation , Intubation, Intratracheal , Laryngeal Masks , Resuscitation Orders , Adult , Age Factors , Aged , Child , Humans , Intubation, Intratracheal/instrumentation , Medical Futility , Multiple Organ Failure , Terminally Ill
19.
J Pept Res ; 55(4): 318-24, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10798377

ABSTRACT

Leptin plays a role in regulating the body weight in mice. Injection of recombinant mouse leptin expressed in Escherichia coli reduced the food intake and body weight in normal, ob/ob and diet-induced obesity mice. Hyperglycemia, hyperinsulinemia and hypothermia can also be corrected in ob/ob mice after leptin injection. Leptin is a 16-kDa secretory protein comprising 167 amino acids produced in adipose tissue and is secreted to blood stream. In this study, a recombinant mouse leptin was generated and purified from a baculovirus expression system. This protein was used to identify putative ligands using a phage library of random peptides. Three leptin-binding phage clones were found, which were characterized by DNA sequencing and ELISA methods. The amino acid sequences of the reactive peptides are: LAYCSDPVRCLVWWY, MFWISAVSFVDHALV and LVLVLSAFLCCGVG. All three clones bound to recombinant human and mouse leptins. These peptides may be useful tools to study leptin-receptor interaction, food intake and body weight regulation.


Subject(s)
Leptin/metabolism , Peptides/metabolism , Amino Acid Sequence , Animals , Bacteriophages/metabolism , Baculoviridae/genetics , Base Sequence , Cell Line , Enzyme-Linked Immunosorbent Assay , Escherichia coli/genetics , Escherichia coli/metabolism , Genetic Vectors , Humans , Insecta/cytology , Leptin/chemistry , Leptin/genetics , Ligands , Mice , Molecular Sequence Data , Peptide Library , Peptides/genetics , Peptides/isolation & purification , Protein Binding , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Sequence Analysis, DNA
20.
Ann Acad Med Singap ; 29(6): 704-7, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11269973

ABSTRACT

INTRODUCTION: The pathogenic importance of antineutrophil cytoplasmic antibodies (ANCAs) in inflammatory bowel disease (IBD) is unclear and target antigen localisation studies may lend insight to the specific pathogenic mechanisms of IBD. In this pilot study, we looked at occurrence of ANCA in Asian IBD patients. In ANCA-positive samples, we analysed for the presence of target antigens i.e. proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme. MATERIALS AND METHODS: This prospective study was carried out from July 1997 to February 1998. Sera were screened for ANCAs with indirect immunofluorescent test and tested with an enzyme immunoassay (ELISA) kit which provides a semi-quantitative assay for human IgG autoantibodies against 6 antigens: proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme. RESULTS: A total of 75 patients were studied: 50 with IBD and 25 controls with functional bowel disease. Ten had Crohn's disease (CD) and 40 had ulcerative colitis (UC). There was no racial predilection among the Chinese, Malays or Indians. In CD, 1 was positive for cytoplasmic ANCA (cANCA) and 2 for perinuclear ANCA (pANCA). In UC, 4 were positive for pANCA, 15 for atypical perinuclear ANCA (apANCA) and 1 for cANCA. In the CD and UC population, the proportion positive for ANCA was 30% and 50%, respectively. There was no ANCA detected among the controls. Of those ANCA-positive IBD patients (n:23), only 1 demonstrated anti-myeloperoxidase antibodies. No antibodies were detected against the other 5 antigens tested. CONCLUSIONS: This pilot Singapore study concludes that there is no significant ANCA association with proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme.


Subject(s)
Antibodies, Antineutrophil Cytoplasmic/analysis , Biomarkers/analysis , Inflammatory Bowel Diseases/diagnosis , Inflammatory Bowel Diseases/immunology , Adult , Aged , Cathepsin G , Cathepsins/analysis , Enzyme-Linked Immunosorbent Assay , Female , Fluorescent Antibody Technique, Indirect , Humans , Lactoferrin/analysis , Male , Middle Aged , Muramidase/analysis , Myeloblastin , Pancreatic Elastase/analysis , Peroxidase/analysis , Pilot Projects , Prognosis , Prospective Studies , Reference Values , Sensitivity and Specificity , Serine Endopeptidases/analysis , Singapore
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