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Tan KBL, Fook-Chong SMC, Lee SL, Tan LK. Foetal peak systolic velocity in the middle cerebral artery: an Asian reference range. Singapore Med J 2009; 50:584-586. [PMID: 19551310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
INTRODUCTION The aim of this study was to establish reference values of peak systolic blood flow velocity measurement in the foetal middle cerebral artery (MCA-PSV) in the local Asian obstetric population and to compare our reference ranges with those of previously-published studies. METHODS 329 normal pregnant women attending the outpatient antenatal clinics of the Department of Obstetrics and Gynaecology in the Singapore General Hospital underwent Doppler ultrasonography at least once between 16 and 40 weeks' gestation. The blood flow velocity recordings from the foetal middle cerebral artery were obtained. New reference ranges were constructed by regressing each parameter on gestational age. RESULTS New reference ranges for foetal middle cerebral artery with gestation were constructed for an Asian population. Our reference curves were compared with that of a previously-constructed one. CONCLUSION MCA-PSV increases with advancing gestational age. There appear to be differences between Asian and non-Asian reference ranges for MCA-PSV.
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Chee CYI, Chong YS, Ng TP, Lee DTS, Tan LK, Fones CSL. The association between maternal depression and frequent non-routine visits to the infant's doctor--a cohort study. J Affect Disord 2008; 107:247-53. [PMID: 17869346 DOI: 10.1016/j.jad.2007.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 08/08/2007] [Accepted: 08/08/2007] [Indexed: 11/30/2022]
Abstract
BACKGROUND Perinatal depression is common, but women typically do not seek help for it. We studied its association with frequent non-routine physician visits, which may be a form of help-seeking behaviour. METHODS A prospective cohort study of women in their 34th to 38th week of pregnancy at the outpatient obstetrics clinic at a Singapore tertiary hospital was done. Screening was done using the Edinburgh Postnatal Depression Scale and diagnosis of major or minor depressive disorder was made using the SCID-IV. At 6 to 12 months' post-partum, women were screened and interviewed again for depression and asked to report the frequencies with which they had brought their infants to the doctor on non-routine visits in the preceding 6 weeks. Four hundred and seventy-one of the 559 patients recruited before delivery were re-interviewed. RESULTS After adjusting for confounders, women who had brought their infants for three or more non-routine visits to the infant's doctor had a significantly higher prevalence of depression (32.6%) than those with fewer visits (13.6%) (OR 2.87, 95% CI 1.41 to 5.85, p=0.004). The relative risk reduction for women who did not bring their infants for frequent non-routine visits was 0.583 (95% CI 0.44 to 0.73, p=0.002). They were also more likely to have poorer perceived emotional support from their families. LIMITATIONS These included use of self-reported doctor visits, and relatively high educational levels of the participants. CONCLUSIONS Doctors should have a high index of suspicion for enquiring about depression and emotional support in mothers who bring their infants for frequent non-routine visits.
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Yeo WT, Tan LK, Dan YY, Wai CT. Delayed bleeding after liver biopsy: a dreaded complication. Singapore Med J 2008; 49:76-80. [PMID: 18204774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present an unusual case of percutaneous liver biopsy complicated by delayed haemothorax in a 55-year-old Chinese man with hepatitis C cirrhosis and severe haemophilia A. The patient presented ten days after the initial liver biopsy, and was managed with prompt investigations for confirming the diagnosis, infusion of factor VIII and fresh frozen plasma, and early referral to the surgeon for consideration of surgical repair. The importance of early detection and aggressive therapy is emphasised.
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Thia EWH, Lee SL, Tan HK, Tan LK. Ultrasonographical features of morbidly-adherent placentas. Singapore Med J 2007; 48:799-802; quiz 803. [PMID: 17728958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Morbidly-adherent placentas manifest as placenta accreta, increta or percreta, depending on the depth of placental invasion. These conditions present high risks of severe obstetrical haemorrhage at delivery. The underlying pathology is due to defects in the decidua basalis caused by a variety of insults, such as previous surgery, excessive curettage or infection. The incidence of morbidly-adherent placentas is rising as the frequency of caesarean sections increase. Imaging plays an important role in the antenatal detection of this condition. Based on the case series seen at our local institution, we describe the imaging characteristics of this condition as seen on grayscale ultrasonography, colour/power Doppler ultrasonography, three-dimensional ultrasonography and magnetic resonance imaging.
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Devendra K, Ching CK, Tan LK, Tan HK, Yu SL. Intrapartum maternal sinus bradycardia with spontaneous resolution following delivery. Singapore Med J 2006; 47:971-4. [PMID: 17075666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Pregnancy is a normal physiological state that is characterised by significant adaptive changes, many of which take place in the cardiovascular system. These adaptations are believed to be the cause for the increased incidence in cardiac arrhythmias in pregnancy and particularly, in labour. We report an unusual case of a healthy 32-year-old primigravida who developed profound intrapartum bradycardia which persisted throughout labour. Spontaneous recovery to pre-labour baseline heart rate occurred following spontaneous vaginal delivery. Maternal and foetal statuses remained satisfactory during labour. This case report underscores the importance of recognising that arrhythmias in various forms are common in labour. In the absence of detectable underlying cardiac disease or maternal and foetal compromise, continuation of the labour with a view to vaginal delivery should be the goal.
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Tan LK, Huang CH, Kuo IC, Liew LM, Chua KY. Intramuscular immunization with DNA construct containing Der p 2 and signal peptide sequences primed strong IgE production. Vaccine 2006; 24:5762-71. [PMID: 16740347 DOI: 10.1016/j.vaccine.2006.04.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 04/20/2006] [Accepted: 04/25/2006] [Indexed: 11/25/2022]
Abstract
BACKGROUND Previous studies demonstrated that allergen gene vaccination induced TH1-skewed responses and inhibited IgE production. This study evaluated and characterized the immune responses induced by three DNA constructs encoding different forms of Der p 2 for safe and efficacious vaccination against mite allergy. METHODS Mice were immunized intramuscularly with DNA constructs encoding a major mite allergen, Der p 2, without a signal peptide (p2), with a signal peptide (p52), and with a signal peptide plus lysosomal-targeting sequence (p52-LA), respectively, followed by TH2-skewed protein challenge. Antibody and T-cell cytokine responses were assessed by ELISA. Primed dendritic cells (DCs) were adoptively transferred to naïve mice and humoral responses were examined after protein challenge. The circulating Der p 2 protein was detected by sandwich ELISA. RESULTS Mice immunized with p52-LA showed strong and clear-cut TH1-type response, as evident by high IFN-gamma production and elevated levels of Der p 2-specific IgG2a production whereas construct p2 induced only moderate levels of TH1 response. In contrast, mice immunized with construct p52 showed a mixed TH1/TH2 phenotype and produced substantial circulating Der p 2 protein. Mice adoptively transferred with DCs primed by p52 construct, but not by the p2 or p52-LA constructs, were sensitized to produce high levels of Der p 2-specific IgE. CONCLUSIONS Immunization with DNA construct encoding a signal peptide could potentially prime TH2-skewed responses and IgE production. The additional inclusion of lysosomal-targeting sequences to such construct could improve the safety and efficacy of DNA vaccination against allergy.
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Tan TC, Devendra K, Tan LK, Tan HK. Tocolytic treatment for the management of preterm labour: a systematic review. Singapore Med J 2006; 47:361-6. [PMID: 16645683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Spontaneous preterm labour and delivery accounts for approximately one-third of preterm births, which is the predominant cause of perinatal mortality and morbidity. This review aims to evaluate the evidence on the benefits and harms of five classes of tocolytic therapy, namely: betamimetics, calcium channel blockers, magnesium, non-steroidal anti-inflammatory agents, and atosiban. We performed a systematic review of the effectiveness of tocolytics to stop uterine contractions (first-line therapy). Reports of randomised controlled trials from searches of MEDLINE, bibliographies of review articles, Cochrane Collaboration and its Pregnancy and Childbirth Review Group between 1966 and 2003 were identified, using the search terms "randomised controlled trial" (RCT), "preterm labor", "tocolysis", "betamimetics", "ritodrine", "prostaglandin synthetase inhibitors", "indomethacin", "calcium channel blockers", "nifedipine", "oxytocin receptor blockers", "atosiban", and "magnesium sulphate". Studies on women with preterm labour comparing the effects of a tocolytic with a placebo or no treatment that met our inclusion criteria, were included. To our knowledge, the trials were conducted mainly before 1999 and there were no placebo-controlled trials after that. Of the 86 articles identified and evaluated, 14 first-line studies met more stringent requirements for meta-analyses. Tocolytics were associated with significant decreases in the odds of delivery within 24 hours (odds-ratio [OR] 0.54, 95 percent confidence interval [CI] 0.32-0.91) and 48 hours (OR 0.47, 95 percent CI 0.30-0.75). These effects were significant for beta-agonists, atosiban and indomethacin, but not magnesium sulphate. Maternal side-effects significantly associated with betamimetics were pulmonary oedema, cardiac arrhthymias and hypokalaemia. Although calcium antagonists have not been evaluated against placebo, comparative trials with beta-agonists have shown more favourable neonatal outcomes and better prolongation of gestation. In conclusion, the management of threatened preterm labour with first-line tocolytic therapy can prolong gestation. However, the time gained in-utero need to be optimised. There is no clear first-line tocolytic agent. The use of tocolytic agents should be individualised and based on maternal condition, potential side-effects and gestational age.
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Chee CYI, Lee DTS, Chong YS, Tan LK, Ng TP, Fones CSL. Confinement and other psychosocial factors in perinatal depression: a transcultural study in Singapore. J Affect Disord 2005; 89:157-66. [PMID: 16257451 DOI: 10.1016/j.jad.2005.09.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 09/16/2005] [Accepted: 09/16/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND To investigate the prevalence, socio-cultural and psychosocial risk factors for perinatal depression in Singaporean women. METHOD A prospective cohort of 559 women was interviewed antenatally and at six weeks' postpartum at a tertiary hospital. Women were interviewed for diagnosis of depression using a two-stage design, with a screening questionnaire and diagnostic interview. RESULTS Postnatally, a negative confinement experience was associated with depression. Other independent factors included poor emotional support, a past history of depression, unplanned pregnancy and perceived potential conflicts with relatives over childcare antenatally and dissatisfaction, poor instrumental support postnatally. The prevalence of depression antenatally and postnatally was 12.2% and 6.8%, respectively. LIMITATIONS Measures of satisfaction with social support were based on self-report; there were high dropout rates at six weeks' postpartum; and other modulating social factors such as pre-existing interpersonal conflicts were not studied. CONCLUSIONS Perinatal depression in Singaporean women is common. Contrary to expectations, a negative 'confinement' experience is a significant risk factor for postnatal depression, and is not universally welcomed by women. Depression is modulated by dissimilar sets of psychosocial factors antenatally and postnatally.
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Lau LG, Tan LK, Koay ESC, Liu TC. Acute lymphoblastic leukemia after tandem autologous stem cell transplantations for multiple myeloma. Leukemia 2004; 19:299-301. [PMID: 15526017 DOI: 10.1038/sj.leu.2403587] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lau LG, Tan LK, Salto-Tellez M, Koay ESC, Liu TC. T-cell post-transplant lymphoproliferative disorder after hematopoietic stem cell transplantation: another case and a review of the literature. Bone Marrow Transplant 2004; 34:821-2. [PMID: 15354208 DOI: 10.1038/sj.bmt.1704677] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lau LG, Chng WJ, Liu TC, Tan LK, Ong KH, Mow BMF, Kueh YK. Clinico-pathological analysis of myelodysplastic syndromes according to French-American-British classification and international prognostic scoring system. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:589-95. [PMID: 15531954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
INTRODUCTION The aim of this study was to analyse the clinico-pathological features of a cohort of patients with myelodysplastic syndromes (MDS). MATERIALS AND METHODS The clinical and pathological data of 43 MDS patients over a 3-year period were reviewed. Survival analysis was performed according to the French-American-British (FAB) classification and International Prognostic Scoring System (IPSS) using the Kaplan-Meier method. Selected published studies for comparison were identified from MEDLINE search. RESULTS The patients were followed up for a median duration of 175 days (range, 2 to 1044 days). The median survival for refractory anaemia (RA) and refractory anaemia with ringed sideroblasts (RARS) has not been reached, but that for refractory anaemia with excess blasts (RAEB), refractory anaemia with excess blasts in transformation (RAEB-T) and chronic myelomonocytic leukaemia (CMML) was 250 days, 49 days and 44 days, respectively. The median survival for the low-risk and intermediate-1 IPSS categories has not been reached, while that for the intermediate-2 and high-risk categories was 58 days and 49 days, respectively. The survival analyses, according to the FAB classification and IPSS system, were statistically significant (P <0.05). Comparison of our data with those from neighbouring and Western countries revealed both similarity and disparity. We also noted different cytogenetic information in our cohort of patients. CONCLUSIONS We found distinctly unique cytogenetic and clinico-pathological characteristics in our MDS patients. However, whether true biological differences exist among MDS patients in different geographies and populations with different genetic and environmental backgrounds require further large multinational study.
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Abstract
AIMS The effects of pH and excipients on the stability of saquinavir in extemporaneously prepared suspensions were assessed. The stability of a developed extemporaneously prepared saquinavir suspension was then determined at 5 and 25 degrees C over 30 days. METHOD Extemporaneous saquinavir 2 mg/mL formulations were prepared from soft gelatin capsule (Fortovase). Four batches of the formulations were buffered at pHs 2, 4, 5 and 7, whereas the other five batches were prepared in Milli-Q water, 0.5% (w/v) citric acid, 0.1% (w/v) sodium ascorbate, 10% (v/v) syrup and in vehicle containing both 0.5% (w/v) citric acid and 0.1% (w/v) sodium ascorbate. The stability of these formulations was tested at 25 degrees C. A final formulation of saquinavir suspension (60 mg/mL) containing both 10% (v/v) syrup and 0.5% (w/v) citric acid was developed and tested for stability at 5 and 25 degrees C for up to 30 days using a stability-indicating high-performance liquid chromatographic method. RESULTS Saquinavir was most stable at pH 2-4. Formulations containing sodium ascorbate, citric acid and syrup or both citric acid and sodium ascorbate were significantly more stable than the control formulation (saquinavir 2 mg/mL in Milli-Q water). CONCLUSION The pH for optimal stability of saquinavir was around 2-4. Besides pH adjustment, saquinavir could also be stabilized by adding anti-oxidants. The saquinavir 60 mg/mL formulation prepared with about a pH of about 4 was stable at both 5 and 25 degrees C for at least 30 days.
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Tan WC, Tan LK, Tan HK, Tan AS. Audit of 'crash' emergency caesarean sections due to cord prolapse in terms of response time and perinatal outcome. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2003; 32:638-41. [PMID: 14626792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
OBJECTIVE The objective was to audit 'crash' emergency caesarean sections (CS) with respect to response time (the diagnosis to delivery interval [DDI]) and perinatal outcome. MATERIALS AND METHODS The computerised database at the Singapore General Hospital (SGH) delivery suite was used to identify all cases of 'crash' emergency CS activated for the diagnosis of cord prolapse from 1992 to 2002. Patients' case notes and neonatal charts were reviewed and the following variables were evaluated: parity, gestational age at the time of delivery and the DDI. Neonatal outcome was measured by Apgar scores at 1 and 5 minutes, cord pH and admission to the neonatal intensive care unit (NICU). RESULTS A total of 34 cases of umbilical cord prolapse were identified from 29,867 deliveries, giving an incidence of 0.11% (1 in 900). The median gestational age was 38.5 weeks (range, 25 to 41 weeks). The median time from diagnosis to delivery was 20 minutes (range, 10 to 40 minutes). Seventy-six percent (19/30) were delivered within 30 minutes. The time of diagnosis was not recorded for 5 cases. Sixty-three percent of neonates had an Apgar score < or = 7 at 1 minute of life, increasing to 97% at 5 minutes. There were 3 NICU admissions for reasons of prematurity. There was no perinatal mortality. Cord pH was not performed for 47% of (14/30) neonates. Among the remaining 16 neonates, an umbilical cord pH of < or = 7.20 was found in 62% (10/16). There was poor correlation between the DDI and umbilical cord pH. CONCLUSION Three-quarters of our 'crash' emergency CS for cord prolapse were performed within 30 minutes with a good perinatal outcome. However, we have identified areas for improvement to optimise further the operational efficiency of 'crash' emergency CS.
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Tan LK. Obstetric cholestasis: current opinions and management. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2003; 32:294-8. [PMID: 12854371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Obstetric cholestasis (OC) is a pregnancy-specific liver condition that typically presents with generalised pruritus in the absence of a rash in the late second trimester or third trimester. It is more common in certain ethnic groups, particularly those from South Asian, South American, Nordic and Scandinavian regions, and has a familial and genetic basis. Recent research suggests that the pathophysiology may reside in mutations in genes that code for bile acid transporter proteins. Mutations involving the bile acid transporters may impair maternal excretion and influence transplacental passage of bile acids. It is hypothesised that the surge in pregnancy steroid hormones may result in genetically predisposed women developing cholestasis. The condition is also associated with increased perinatal morbidity and mortality, particularly from preterm labour, fetal distress and intrauterine deaths. Animal studies have shown that bile acids are cardiotoxic, which may help explain the condition's association with fetal distress and stillbirths. Accurate diagnosis relies on a high index of suspicion, and the findings of abnormal liver function tests and raised serum bile acid levels after the exclusion of other organic causes of liver disease. Ursodeoxycholic acid helps relieve symptoms, improve serum bile acid levels and possibly has a cardioprotective effect. Active management, in the form of close antepartum fetal monitoring and delivery before 37 weeks, helps to decrease the risk of intrauterine deaths, though possibly at the expense of increased obstetric intervention. Following delivery, there is usually a dramatic improvement of symptoms and resolution of the condition. Women should be counselled about the high recurrence risk of OC in subsequent pregnancies.
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Bevilacqua J, Cody H, MacDonald KA, Tan LK, Borgen PI, Van Zee KJ. A prospective validated model for predicting axillary node metastases based on 2,000 sentinel node procedures: the role of tumour location [corrected]. EUROPEAN JOURNAL OF SURGICAL ONCOLOGY 2002; 28:490-500. [PMID: 12217300 DOI: 10.1053/ejso.2002.1268] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIMS The purpose was to identify the independent predictive factors of axillary lymph-node metastases (ALNM) in infiltrating ductal carcinoma (IFDC) and to create a prospective, validated statistical model to predict the likelihood of ALNM in patients in the present era of sentinel lymph-node (SLN) biopsy and enhanced histopathology. METHODS Univariate and multivariate analyses of 13 clinicopathological variables (including tumour location) were performed to determine predictors of ALNM in 1659 eligible SLN biopsy procedures. A logistic regression model was developed and then prospectively validated on a second population of 187 subsequent consecutive procedures. RESULTS Age, pathological tumour size, palpability, lymphovascular invasion (LVI), histological grade, nuclear grade, ductal histological subtype, tumour location (quadrant) and multifocality were associated with ALNM in univariate analyses (P < 0.001). Of these, only palpability and histological grade were not statistically associated with ALNM in the multivariate analysis (P> 0.05). The frequency of ALNM in upper-inner-quadrant (UIQ) tumours was 20.6%, compared with 33.2% for all other quadrants (P<0.0005). There was no statistical difference between UIQ and other-quadrant tumours in any clinicopathological variables analysed. The logistic regression model, developed based on the population of 1659, had the same accuracy, sensitivity, specificity, positive predictive value and negative predictive value when applied prospectively to the second population. CONCLUSION Tumour size, LVI, age, nuclear grade, histological subtype, multifocality and location in the breast were independent predictive factors for ALNM in IFDC. ALNM is less frequent in UIQ tumours than in other-quadrant tumours. Our prospectively validated predictive model could be valuable in pre-operative patient discussions, although staging of the axilla in the individual patient remains necessary.
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Tan LK, de Swiet M. Management of thromboembolic disease in pregnancy. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2002; 31:311-9. [PMID: 12061291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Venous thromboembolism (VTE) is the leading cause of maternal mortality and morbidity in developed countries including Singapore. The physiological changes of pregnancy and other factors, such as maternal age, parity, obesity, operative delivery, general anaesthesia and congenital and acquired thrombophilia, further increase the risk of VTE throughout all three trimesters of pregnancy, including the puerperium. VTE has a wide spectrum of clinical presentations and a high index of clinical suspicion is vital. Clinicians should not withhold the use of chest X-rays and ventilation-perfusion (V/Q) lung scans in pregnancy as the radiation emitted is well within the safety limits to the fetus. Most treatment guidelines are based on studies in non-pregnant populations. Heparin is the preferred anticoagulant as it does not cross the placenta and therefore carries no teratogenic risk to the fetus. There is increasing experience and confidence in the use of fixed dose subcutaneous low molecular weight heparin (LMWH) which removes the need for cumbersome monitoring, thereby allowing outpatient treatment. LMWH may also have a lower risk of osteopaenic complications compared to unfractionated heparin. With the exception of acute phase treatment of pulmonary embolism, LMWH is used in all other aspects of the treatment of VTE in pregnancy, including thromboprophylaxis. Risk stratification of women into high and low risk allows judicious use of anticoagulants for thromboprophylaxis. Antenatal thromboprophylaxis with LMWH is reserved for high-risk women, while low-risk women will only require such cover in the postpartum period.
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Chua HL, Tan LK, Tan HK, Tan ASA, Choong HL. The course of pregnancy in a patient with nail-patella syndrome. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2002; 31:349-52. [PMID: 12061296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
INTRODUCTION The nail-patella syndrome is a rare autosomal dominant condition with high penetrance. Pregnancy in such a patient is rare and we believe this to be the first report of a live birth occurring in a patient with nail-patella syndrome. CLINICAL PICTURE A 25-year-old patient presented in her first pregnancy with nephrotic syndrome associated with characteristic bone abnormalities and nail dysplasia and was later diagnosed to have nail-patella syndrome. In her second pregnancy, the course of her pregnancy was complicated by further deterioration of renal function with superimposed pre-eclampsia resulting in early delivery at 28 weeks. CONCLUSION Such pregnancies should be regarded as high risk and managed jointly with the renal physician in a tertiary care centre to ensure an optimal outcome to the mother and baby.
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Tan LK, Tan HK, Lee CT, Tan ASA. Outcome of pregnancy in Asian women with systemic lupus erythematosus: experience of a single perinatal centre in Singapore. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2002; 31:290-5. [PMID: 12061288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVE To study maternal and fetal outcomes in women with systemic lupus erythematosus (SLE). MATERIALS AND METHODS Retrospective study of 27 pregnancies in 18 women with SLE in a single centre. RESULTS The mean age was 30 years and most patients were nulliparous. Twenty-six of 27 pregnancies were in disease remission at the time of booking. Renal impairment was present in 7 pregnancies (6 women), of whom 2 were in end-stage renal disease on dialysis. Gestational diabetes developed in 4 pregnancies. There were 6 cases of pre-existing hypertension and 5 with superimposed pre-eclampsia. One woman developed intrapartum eclampsia. Two women had secondary antiphospholipid syndrome (APS) and suffered late fetal losses; in addition, they also developed SLE flares in the form of autoimmune haemolytic anaemia in the postpartum period. There was no maternal mortality. There was one termination of pregnancy for severe renal disease. The median gestational age at delivery was 38 weeks (range, 24 to 40 weeks) and the mean birth weight was 3047 g; the median Apgar scores were 8 and 9 at 1 and 5 minutes of life, respectively. There were 5 cases of intrauterine growth restriction (IUGR), 4 of which occurred in women with renal impairment. There were no cases of congenital heart block or neonatal lupus. There was a late fetal loss at 24 weeks in a woman with secondary APS. There were 2 preterm deliveries (7.4%) due to intervention for IUGR. CONCLUSION Good pregnancy outcomes can be expected in women with SLE in remission. Pre-pregnancy counselling is crucial to achieve this. All pregnancies should still be considered high risk and be managed jointly between the obstetricians, the perinatologists and the physicians. In particular, those with renal impairment are at increased risk of IUGR, superimposed pre-eclampsia and preterm births. Co-existing APS augurs a poorer prognosis for pregnancy outcome, and may present atypically as autoimmune haemolytic anaemia in the postpartum period.
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Ang AH, Pang KP, Tan LK. Complete branchial fistula. Case report and review of the literature. Ann Otol Rhinol Laryngol 2001; 110:1077-9. [PMID: 11713922 DOI: 10.1177/000348940111001116] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Branchial anomalies, a result of aberrant embryonic development, are rarely seen in clinical practice. Lesions of the second branchial pouch commonly present as a neck lump or discharging sinus that may be complicated by infection. Clinical examination often reveals the lesion to be related to the junction of the upper two thirds and the lower one third of the sternocleidomastoid muscle. Branchial fistulas often present as a discharging sinus in the neck with the fistula tract extending upward within the deep neck tissue for a variable distance. A complete branchial fistula is one that has a defined internal opening in the tonsillar area and an external opening at the skin overlying the sternocleidomastoid muscle at the junction of the upper two thirds and the lower one third of the muscle. The incidence of such lesions is extremely rare. Surgical excision is the treatment of choice for branchial anomalies. We present the case of a patient who presented with a complete branchial fistula and discuss the clinical presentation and surgical management of such lesions, with a review of the relevant literature.
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Kaptain S, Tan LK, Chen B. Her-2/neu and breast cancer. DIAGNOSTIC MOLECULAR PATHOLOGY : THE AMERICAN JOURNAL OF SURGICAL PATHOLOGY, PART B 2001; 10:139-52. [PMID: 11552716 DOI: 10.1097/00019606-200109000-00001] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Breast cancer is the most common malignancy in women in the United States in the year 2000. The proto-oncogene Her-2/neu (c-erb-B2) has become an increasingly important prognostic and predictive factor in breast cancer. Overexpression/amplification of the Her-2/neu has been associated with a worse outcome in patients with breast cancer. Herceptin, a "humanized" murine monoclonal antibody directed against the extracellular domain of the Her-2/neu protein, is being used to treat breast cancer that overexpresses Her-2/neu. The status of Her-2/neu in the tumor has become a critical factor in the management strategy of a breast cancer patient. The objective of this article is to provide a comprehensive review of all aspects of Her-2/neu in breast cancer, including biology, prognostic and predictive value, targeted Herceptin therapy, and the laboratory testing of Her-2/neu.
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Choong ML, Tan LK, Lo SL, Ren EC, Ou K, Ong SE, Liang RC, Seow TK, Chung MC. An integrated approach in the discovery and characterization of a novel nuclear protein over-expressed in liver and pancreatic tumors. FEBS Lett 2001; 496:109-16. [PMID: 11356193 DOI: 10.1016/s0014-5793(01)02409-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
An integrated approach in protein discovery through the use of multidisciplinary tools was reported. A novel protein, Hcc-1, was identified by analysis of the hepatocellular carcinoma (HCC)-M cell proteome. The assembled EST sequence of the 210 amino acid novel protein was subsequently confirmed by rapid amplification of cDNA ends (RACE). A total of 687 bp at the 5' untranslated region of Hcc-1 was identified. Promoter activity and several upstream open reading frames (uORFs) were demonstrated at this region. Bioinformatics prediction showed that the first 42 amino acids of the protein is a SAP domain with sequence matches to hnRNP from various vertebrate species. The Hcc-1 protein was localized to the cell nucleus while the gene was localized to chromosome 7q22.1. Hcc-1 cDNA level was increased in pancreatic adenocarcinoma. The level was also increased in well-differentiated hepatocellular carcinoma but decreases as the carcinoma progressed to a poorly differentiated stage.
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MESH Headings
- 5' Untranslated Regions
- Adenocarcinoma/metabolism
- Amino Acid Sequence
- Amino Acids/chemistry
- Base Sequence
- Blotting, Western
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Cell Nucleus/metabolism
- Chromosome Mapping
- Chromosomes, Human, Pair 7
- DNA/metabolism
- DNA, Complementary/metabolism
- Electrophoresis, Gel, Two-Dimensional
- Expressed Sequence Tags
- Humans
- Hydrogen-Ion Concentration
- Liver Neoplasms/genetics
- Liver Neoplasms/metabolism
- Mass Spectrometry
- Microscopy, Fluorescence
- Molecular Sequence Data
- Nuclear Proteins/biosynthesis
- Nuclear Proteins/genetics
- Open Reading Frames
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Promoter Regions, Genetic
- Protein Structure, Secondary
- Protein Structure, Tertiary
- RNA/metabolism
- Recombinant Proteins/metabolism
- Sensitivity and Specificity
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Tissue Distribution
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Weiser MR, Montgomery LL, Tan LK, Susnik B, Leung DY, Borgen PI, Cody HS. Lymphovascular invasion enhances the prediction of non-sentinel node metastases in breast cancer patients with positive sentinel nodes. Ann Surg Oncol 2001; 8:145-9. [PMID: 11258779 DOI: 10.1007/s10434-001-0145-y] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Fifty percent of patients with sentinel lymph node (SLN) metastases have no metastatic disease in non-SLNs on axillary lymph node dissection (ALND). The goal of this study is to determine which patients have metastatic disease limited to the SLN, and, therefore, may not require completion ALND. METHODS Of the first 1000 patients undergoing SLN biopsy at Memorial Sloan-Kettering Cancer Center, using a combined blue dye and isotope technique, 231 (26%) had positive SLN. Of these, 206 underwent completion ALND. They are the study group for this report. RESULTS The likelihood of non-SLN metastasis was inversely related to three clinicopathologic variables: tumor size < or = 1.0 cm; absence of lymphovascular invasion (LVI); and SLN micrometastases (< or = 2 mm). None of 24 patients with all three predictive factors had non-SLN metastases, whereas 58% of patients with none of the factors had disease in the non-SLN. CONCLUSION Patients with small breast cancers, no LVI, and SLN micrometastases have a low risk of non-SLN metastases, and may not require completion ALND.
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Tang KF, Tan SY, Chan SH, Chong SM, Loh KS, Tan LK, Hu H. A distinct expression of CC chemokines by macrophages in nasopharyngeal carcinoma: implication for the intense tumor infiltration by T lymphocytes and macrophages. Hum Pathol 2001; 32:42-9. [PMID: 11172294 DOI: 10.1053/hupa.2001.20886] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is characterized by harboring Epstein-Barr virus genes in the tumor cells and an intense infiltration of leukocytes in the tumor tissue. These infiltrating cells are mainly composed of T lymphocytes and macrophages. The mechanism of this intense infiltration has long been a puzzle. We attempted to address this issue by studying the expression of CC chemokines, which are responsible for recruiting both T cells and macrophages, by an immunohistochemical approach. In biopsies obtained from nasopharynx of 17 NPC patients that contained tumor cells, expression of macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, macrophage chemoattractant protein-1 (MCP-1), MCP-2, MCP-3, and RANTES was detected in the tumor-infiltrating cells, with MIP-1alpha and MCP-1 found in nearly all biopsies and the others relatively less frequently. Furthermore, expression of interferon-gamma (IFN-gamma) was also observed in tumor-infiltrating cells. In contrast, CC chemokines and IFN-gamma were rarely expressed in the 13 control biopsies that were either normal or with nonspecific inflammation, and in 4 biopsies from untreated NPC patients that contained no tumor cells. Using an immunofluorescent double-staining method, MIP-1alpha and MCP-1 were identified to be associated with macrophages, and IFN-gamma with T cells. Moreover, expression of CCR2 and CCR5, the receptors for these chemokines, was also detected in the tumor-infiltrating cells. These data indicate that the intense tumor infiltration by T cells and macrophages is a result of active recruitment. It seems possible that the intense infiltration of leukocytes in NPC tumor tissue is initiated by the activated tumor-reactive T cells. T cells migrate into the tumor tissue in an antigen-specific mode, and IFN-gamma secreted from these pioneer T cells activates tissue macrophages to express CC chemokines, especially MIP-1alpha and MCP-1, which consequently recruit more T cells and macrophages into the tumor tissue.
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MESH Headings
- Antibodies, Viral/blood
- Chemokines, CC/biosynthesis
- Herpesvirus 4, Human/genetics
- Herpesvirus 4, Human/immunology
- Humans
- Immunoglobulin A/blood
- Immunohistochemistry
- In Situ Hybridization
- Interferon-gamma/biosynthesis
- Lymphocytes, Tumor-Infiltrating/chemistry
- Lymphocytes, Tumor-Infiltrating/pathology
- Macrophages/chemistry
- Macrophages/pathology
- Nasopharyngeal Neoplasms/immunology
- Nasopharyngeal Neoplasms/metabolism
- Nasopharyngeal Neoplasms/pathology
- RNA, Viral/genetics
- Receptors, CCR2
- Receptors, CCR5/biosynthesis
- Receptors, Chemokine/biosynthesis
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Ho GH, Calvano JE, Bisogna M, Borgen PI, Rosen PP, Tan LK, Van Zee KJ. In microdissected ductal carcinoma in situ, HER-2/neu amplification, but not p53 mutation, is associated with high nuclear grade and comedo histology. Cancer 2000; 89:2153-60. [PMID: 11147584 DOI: 10.1002/1097-0142(20001201)89:11<2153::aid-cncr2>3.0.co;2-o] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND HER-2/neu and p53 are two molecular markers that have been the focus of investigation in patients with invasive breast carcinoma. However, most of the published data have relied on immunohistochemical detection of the proteins as a surrogate marker of the underlying genetic alterations, a detection method that often gives variable results due to technical factors. In addition, there are limited data documenting HER-2/neu amplification and p53 mutations in the various histologic subtypes of ductal carcinoma in situ (DCIS). The authors evaluated a series of microdissected, pure DCIS lesions comprising a spectrum of morphologic subtypes (comedo, micropapillary, papillary, cribriform, and solid) and their corresponding normal breast tissue for genetic aberrations in HER-2/neu and p53. METHODS HER-2/neu amplification was determined by differential polymerase chain reaction, and p53 mutations were identified by single-strand conformation polymorphism analysis. RESULTS HER-2/neu amplification was identified in 12 of 30 DCIS samples (40%), and p53 mutations were identified in 6 of 30 DCIS samples (20%). The genetic alterations were not present in any of the normal breast tissue samples. HER-2/neu amplification occurred predominantly in the comedo subtype (69% vs. 18% of the noncomedo subtype; P = 0.008) and in lesions of high nuclear grade (63% vs. 14% of low grade; P = 0.01). There was no difference in the frequency of p53 mutations among the subtypes or between low grade and high grade lesions. No correlation between the presence of the two genetic alterations was observed. CONCLUSIONS The presence of HER-2/neu amplification, but not p53 mutations, correlates with histologic subtype and nuclear grade. The relatively frequent occurrence of HER-2/neu amplification and p53 mutations in DCIS tissue and their absence in normal breast tissue suggest that these genetic aberrations are important early in breast duct carcinogenesis.
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MESH Headings
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Breast Neoplasms/surgery
- Carcinoma in Situ/genetics
- Carcinoma in Situ/pathology
- Carcinoma in Situ/surgery
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Ductal, Breast/surgery
- Cell Nucleus/pathology
- DNA, Neoplasm/genetics
- Gene Amplification
- Genes, erbB-2/genetics
- Genes, p53/genetics
- Genetic Markers/genetics
- Humans
- Mutation
- Phenotype
- Polymerase Chain Reaction/methods
- Polymorphism, Single-Stranded Conformational
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Loh KS, Tan LK, Smith JD, Yeoh KH, Dong F. Complications of foreign bodies in the esophagus. Otolaryngol Head Neck Surg 2000; 123:613-6. [PMID: 11077351 DOI: 10.1067/mhn.2000.110616] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Major complications of foreign bodies in the esophagus carry significant morbidity and mortality risks. A retrospective case control study was performed to assess the factors associated with major complications. In total, 273 patients seen within a 7-year period were divided into 2 groups; 253 had no or minor complications, and 20 had major complications. Age, sex, duration of the foreign body, total white cell count (TWC), and nature and site of the foreign body were analyzed in the 2 groups. The major complication rate was 7.3%. Duration of the foreign body and TWC were the only statistically significant factors associated with major complications. Six patients required open neck exploration, 1 had an open thoracotomy, and 13 were treated by endoscopic removal. There were 2 deaths. Given the significant morbidity and mortality risks, we conclude that patients with a prolonged history of a foreign body in the esophagus and a raised TWC should be treated urgently.
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