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Biomedical subjects

C L Yeo

Publications and source records attributed to C L Yeo.

12 recordsLinked to original sources
PubMed2005

Genetic diversity and variation of saponin contents in Panax notoginseng roots from a single farm.

Radix notoginseng, the root of Panax notoginseng (Burk.) F. H. Chen, has been widely used in traditional Chinese medicine. Its main components, saponins, have been reported to have many pharmacological activities. To test the general assumption that herbs of a single species planted and harvested from a single location are uniform in chemical and genetic makeup, chemical analysis and DNA fingerprinting were carried out. High-performance TLC together with HPLC analysis were used to analyze 17 randomly sampled 3-year-old roots from a single farm for the presence of six saponins. Five roots showed distinct chemical profiles with changed ratios of ginsenosides Rd/Rg1, Re/Rg1, or Rb1/Rg1. The same samples, together with some 1- and 2-year-old samples, were also subjected to fluorescent amplified fragment length polymorphism (AFLP) analysis, and their internal transcribed spacer 2 (ITS 2) regions were sequenced. Fluorescent AFLP analysis was found to be much more polymorphic than the ITS 2 sequence and showed clear evidence of genetic diversity within the tested population. In conclusion, genetic diversity and variation of saponin contents between individual P. notoginseng roots have been detected. We suggest that genetic diversity affects the contents of the six saponins. The saponin contents variation and genetic diversity were also found among P. notoginseng root samples collected from China and Singapore markets. Since variable saponin contents may affect therapeutic efficacy, combining the use of genetic profiling with chemical profiling will help ensure greater uniformity in the quality of P. notoginseng roots. The genetic and chemical diversity within a population also provides the opportunity for breeding new cultivars with more desirable chemical constituents.

Base Sequence↗
PubMed2005

Incidence, risk factors of retinopathy of prematurity among very low birth weight infants in Singapore.

INTRODUCTION: To determine the incidence, risk factors and need for surgery for retinopathy of prematurity (ROP) among very-low-birth-weight (VLBW) infants. MATERIALS AND METHODS: This was a retrospective study of all VLBW infants managed by the department over 14 years, from 1988 to 2001. Preterm infants were examined according to the Royal College of Ophthalmologists' guidelines, and retinopathy was graded following the International Classification of ROP. All VLBW infants examined for ROP were included and data were retrieved retrospectively and analysed for maternal, medical, obstetric and neonatal risk factors using logistic regression. RESULTS: Of the 564 VLBW infants who fit the screening criteria, ROP was detected in 165 (29.2%) of VLBW infants; of whom 49% of infants had stage 1 disease, 24% were at stage 2, and 27% were at stage 3 or more. Among 45 infants with stage 3 disease or more, treatment was needed in 62.2% (28/45). No ROP was detected in infants greater than 33 weeks of gestation. Only 0.6 % (1/164) of infants greater than 30 weeks of gestational age (GA) needed surgery for ROP. Using birth weight (BW) criteria, stage 3 ROP was noted only in 1% (6/564) of infants with BW >1000 g. Of all ROP requiring surgery, 89% (25/28) of infants were <1000 g as compared to 11% (3/28) who were >1000 g infants. The median age of onset of ROP was 35 weeks (range, 31 to 41) corrected age. By univariate analysis for threshold ROP, preeclampsia, prenatal betamethasone exposure, gestational age, birth weight, 1-minute Apgar score, hyaline membrane disease (HMD), surfactant usage, hypotension, septicaemia, intraventricular haemorrhage duration of supplemental oxygen, ventilation and chronic lung disease were associated with ROP requiring surgery (i.e., threshold ROP, P <0.05). However, using multiple logistic regression analyses for ROP, maternal preeclampsia [odds ratio (OR), 2.52; confidence interval (CI), 1.32 to 4.7], birth weight (OR, 0.99; CI, 0.996 to 0.999), pulmonary haemorrhage (OR, 4.61; CI, 1.04 to 20.4), duration of ventilation (OR, 1.06; CI, 1.04 to 1.08) and duration of continuous positive airway pressure (CPAP) (OR, 1.02; CI, 1.01 to 1.04) were factors predictive of development of threshold ROP. CONCLUSION: The incidence of ROP among VLBW infants was 29.2%. ROP was strongly associated with smaller, more immature and sicker infants. The median age of onset of ROP was 35 weeks (range, 31 to 40 weeks) postmenstrual age. Infants <30 weeks of GA and/or infant with BW <1000 g are at considerable risk for threshold ROP. The main risk factors for development of threshold ROP by regression analysis are maternal preeclampsia, birth weight, and presence of pulmonary haemorrhage, duration of ventilation and continuous positive pressure ventilation. We suggest that both immaturity and compromised pulmonary function are both important aetiological factors in the development of ROP. Prevention of prematurity, control of preeclampsia, judicious use of ventilation and oxygen therapy are the only promising factors that may reduce the incidence and severity of ROP in this high-risk infant.

Gestational Age↗
PubMed2005

Motor development of very low birthweight infants with chronic lung disease - a comparative study.

INTRODUCTION: To determine whether chronic lung disease (CLD) influences specific aspects of motor development in infancy. MATERIALS AND METHODS: Twenty-nine very low birthweight infants with CLD at 36 weeks' post-conceptional age and 31 infants without CLD were evaluated at 8 months' and 24 months' corrected age using the Neurosensory Motor Development Assessment. Perinatal and neonatal characteristics of the infants with CLD and control infants were compared using the chi-square test for categorical variables and Student's t-test for continuous variables. The relationship between CLD and adverse outcome was measured by the odds ratio (OR) and its 95% confidence interval (CI). RESULTS: The overall developmental scores of the CLD infants were significantly different compared with control infants at 8 months. By 2 years of age, both groups of infants showed marked improvement in motor performance. However, differences persisted in the area of postural balance and sensory motor skills. Taking periventricular haemorrhage and periventricular leukomalacia into consideration, CLD contributed significantly to the occurrence of motor dysfunction at 8 months of age [odds ratio (OR), 7.4; 95% confidence interval (CI), 2.1 to 26.5]. The impact of CLD on motor development remained substantial, though not statistically significant (OR, 3.7; 95% CI, 0.4 to 37.9) at 2 years of age. CONCLUSION: CLD has a definite effect on motor development. The pathologic influence of CLD on motor development remains speculative but results of this study emphasise the need for careful neurodevelopmental follow-up of infants with CLD, whether or not these infants suffer intraventricular haemorrhage or periventricular leukomalacia.

Bronchopulmonary Dysplasia↗
PubMed2003

General practitioners' knowledge on childhood developmental and behavioural disorders.

INTRODUCTION: Childhood developmental and behavioural disorders are increasingly being recognised, with high demands for earlier diagnosis and intervention. In Singapore, referrals to the Child Development Unit, KK Women's and Children's Hospital, originate mainly from primary health care practitioners, who therefore should have adequate baseline knowledge of normal development as well as common developmental and behavioural disorders. METHODOLOGY: A pilot study, using a questionnaire survey, was conducted, with the aim of assessing existing knowledge in childhood developmental and behavioural paediatrics amongst a cohort of general practitioners (GPs) in Singapore. True/False questions on normal development as well as developmental disorders such as autistic spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD) and learning disability, were structured. These disorders were selected because of their relatively higher prevalence. RESULTS: A total of 48 GPs were surveyed, representing 2% of non-specialists practising in the private sector. The median total score (T-score) was 9 (range 6 to 13) of a possible 14. Only just over a-third of the group achieved the pass rate (defined arbitrarily as 75%) for T-score, with two-thirds replying correctly to all questions on normal development. Scores for factual ASD/ADHD questions were also not ideal, with some myths being believed as truths. CONCLUSION: The scores reflect knowledge and educational deficits in developmental paediatric medicine amongst the study cohort. Expected to provide holistic care and counselling, these GPs are currently insufficiently equipped with the necessary knowledge and skills to support families of special-needs children. Education and training programmes in this aspect of paediatric medicine are clearly needed, through the organisation of CME lectures and incorporation of various developmental topics into the training curriculum. This will enable early identification and diagnosis of childhood developmental and behavioural disorders, which will in turn allow greater optimisation of potential and functionality in these special-needs children.

Adult↗
PubMed2002

Two-year outcome of normal-birth-weight infants admitted to a Singapore neonatal intensive care unit.

INTRODUCTION: To describe the characteristics, the immediate and short-term outcome and predictors of mortality in normal-birth-weight (NBW) infants admitted to a tertiary neonatal intensive care unit (NICU) in Singapore. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 137 consecutive NBW infants admitted to the NICU of the Singapore General Hospital from January 1991 to December 1992. Data on the diagnoses, clinical presentation of illness, intervention received, complications and outcome as well as follow-up patterns for the first 2 years of life, were collected and analysed. RESULTS: NBW NICU infants comprised 1.8% of births in our hospital and 40.8% of all NICU admissions. The main reasons for NICU admissions were respiratory disorders (61.3%), congenital anomalies (15.3%) and asphyxia neonatorum (11.7%). Respiratory support was necessary in 81.8%. Among those ventilated, the only predictive factor contributing to mortality was the mean inspired oxygen concentration. The mortality rate was 11.7%. Causes of death included congenital anomalies (43.75%), asphyxia neonatorum (31.25%) and pulmonary failure secondary to meconium aspiration syndrome (12.5%). The median hospital stay among survivors (88.3%) was 11.0 (range, 4 to 70) days. Of 42 patients (out of 117 survivors) who received follow-up for at least 6 months, 39 infants did not have evidence of any major neurodevelopmental abnormalities at their last follow-up visit, prior to or at 2 years of age. CONCLUSIONS: Despite their short hospital stay (compared to very-low-birth-weight infants), the high volume of NBW admissions make the care of this population an important area for review to enhance advances in and hence, reduce the cost of NICU care. With improved antenatal diagnostic techniques (allowing earlier and more accurate diagnosis of congenital malformations) and better antenatal and perinatal care (allowing better management of at-risk pregnancies), it is anticipated that there should be a reduction in such admissions with better outcomes. Close follow-up of this high-risk group of infants is also important in order to offer early intervention to those who may possibly have perinatally-related developmental difficulties.

Birth Weight↗
PubMed2001

Effect of recombinant human erythropoietin on transfusion needs in preterm infants.

OBJECTIVE: To study the efficacy, safety and cost effectiveness of recombinant human erythropoietin (r-HuEPO) in reducing erythrocyte transfusion needs in very low birthweight (VLBW) infants. METHODS: We conducted a non-blind randomized controlled trial and assigned 100 VLBW infants, less than 33 weeks gestation, to receive either r-HuEPO 750 U/kg per week subcutaneously from day 5 to day 40 or no erythropoietin (EPO). Infants received oral iron 3-6 mg/kg per day from day 10. Transfusion needs were analysed for all enrolled infants and in five weight subgroups: birthweight of less than 600 g, 600-799 g, 800-999 g, 1000-1199 g and infants more than 1200 g. RESULTS: VLBW infants on r-HuEPO attained higher reticulocyte counts and haematocrit than control infants but the mean number of transfusions and volume of erythrocyte transfused per infant were not statistically different. Of infants 800-999 g at birth, the mean number of transfusions per infant was 2.1 compared with 3.5 transfusions per control infant (P = 0.04). Volume of erythrocytes transfused was 34.9 +/- 32.1 mL/kg in r-HuEPO-treated infants and 56.6 +/- 25.8 mL/kg in control infants (P = 0.03). The cost per patient for transfusion and EPO was S$388 for r-HuEPO recipient and S$438 for control infant. Blood pressure, neutrophil count, platelet count and complications of prematurity were not significantly different in both groups of VLBW infants. CONCLUSION: r-HuEPO at 750 U/kg per week stimulates erythropoiesis in VLBW infants but significantly reduces the need for erythrocyte transfusion only in infants weighing 800-999 g at birth.

Blood Transfusion↗
PubMed1998

Congenital sodium diarrhoea in an Indian girl.

We report the case of a newborn Indian girl with congenital sodium diarrhoea (CSD) who presented typically in utero, in whom diagnosis was made from markedly raised stool sodium in the presence of an alkaline stool. Treatment with sodium citrate normalised her metabolic and electrolyte status but resulted in transient uremia necessitating supplementation with sodium bicarbonate instead. She died at 11 weeks old following re-admission in a moribund state with grossly increased abdominal distension. Her fatal outcome in infancy suggests that CSD has a wide spectrum of clinical severity.

Citrates↗
PubMed1997

Chronic lung disease in very low birthweight infants: a 5-year review.

OBJECTIVES: To determine the incidence, clinical spectrum and outcome of very low birthweight (VLBW) infants with chronic lung disease (CLD), and evaluate associated factors. METHODOLOGY: Retrospective review of 265 VLBW infants managed in the NICU from January 1988 to December 1992. RESULTS: The overall neonatal survival rate for VLBW infants was 83%. Sixty-five (25%) infants had CLD, of whom 42% had severe CLD. Mortality in infants with CLD was 11%. In contrast with infants without CLD, CLD infants had significantly higher risk of adverse neurodevelopment with cerebral palsy documented in 13.5% and functional disability recorded in 34.6% at 2 years corrected age. Factors associated with the development of CLD included; decreasing birthweight (OR 0.98, CI 0.97-0.99), septicaemia (OR 4.96, CI 1.57-15.65), necrotizing enterocolitis (OR 119.07, CI 4.98-2845.04), hyaline membrane disease (OR 5.34, CI 1.83-15.55), patent ductus arteriosus (OR 4.46, CI 1.75-11.36) and increasing fraction of inspired oxygen concentration in the first week of life (OR 1.09, CI 1.04-1.14). CONCLUSIONS: Chronic lung disease occurs frequently in VLBW infants and is associated with a high incidence of adverse neurodevelopment. Further studies to clarify the role of non-respiratory factors such as patent ductus arteriosus (PDA) and sepsis in the pathogenesis of CLD may reduce the incidence or prevent the development of CLD in these preterm infants.

Cerebral Palsy↗
PubMed1994

Outcome of resuscitated apparently stillborn infants: a ten year review.

This study addresses the dilemma of whether to attempt resuscitation of the previously undiagnosed fresh stillborn infant and evaluates factors predictive of survival and long-term outcome. We reviewed the clinical spectrum, immediate complications and long-term outcome of 45 successfully resuscitated apparently stillborn infants (34 term, 11 preterm) who were admitted to the Intensive Care Nursery. Significant obstetric and intrapartum events were identified in 34 (75%) infants while 11 (25%) had no apparent risk factors. Of the 39 infants with neonatal complications, 37 had hypoxic-ischaemic encephalopathy (HIE: Sarnat stage 1 in 5, stage 2 in 15, stage 3 in 17); 12 (27%) had oliguria, 10 (22%) had hypotension, 7 (16%) experienced hypoglycaemia, 4 (9%) had disseminated intravascular coagulopathy (DIC) and 1 (2%) had persistent pulmonary hypertension of the newborn (PPHN). Fourteen infants (31%) died in the neonatal period and four (9%) died during infancy. Risks of death and adverse neurodevelopment were significantly increased in infants with stage 2 or 3 HIE (P < 0.005). Follow-up assessment of 24 of the 27 surviving infants revealed a normal outcome in 15 (63%), severe disability in six (25%), moderate disability in two (8%) and mild disability in one (4%) infant. The positive predictive value of stage 2 or 3 HIE was 70% for mortality and 80% for morbidity. One-third (15/45) of successfully resuscitated apparently stillborn infants were normal at follow-up assessment and the outcome for these infants was predicted with complete accuracy by the stage of HIE present during the neonatal period.

Apgar Score↗
PubMed1994

Inguinal hernia in extremely preterm infants.

The prevalence of inguinal hernia during primary hospitalization was determined in 250 infants with gestational age 24-29 weeks. Fourteen per cent developed hernia, with prevalence significantly higher in boys than girls. Infants with respiratory distress syndrome and those requiring prolonged mechanical ventilation were significantly predisposed to the development of hernia. Male infants, especially those who required prolonged ventilatory assistance, were at greatest risk. This information may be used when counselling parents regarding complications of very preterm infants.

Female↗
PubMed1984

Pelvi-ureteric junction obstruction in Singapore children--a retrospective study.

Thirty-two cases of hydronephrosis caused by pelvi-ureteric junction obstruction, presenting to the Department of Paediatric Surgery in the last 6 years were reviewed. In both infants and older children a palpable abdominal mass was the most common mode of presentation. Anderson-Hynes pyeloplasty was performed in a total of 31 kidneys. In 4 children, whose kidneys were severely hydronephrotic and with hardly any renal parenchyma present a primary nephrectomy was performed. Of the two children who required further operation on the same kidney, a repeat pyeloplasty for persistent obstruction was required in 1 patient, the other patient underwent nephrectomy subsequent to pyeloplasty as a severe pyonephrosis had developed. Twenty-nine of the 31 kidneys were assessed postoperatively by tube nephrogram, intravenous pyelogram (IVP), or diuretic renography. Four kidneys were found to be non-functional or severely damaged.

Child↗