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Biomedical subjects

F T Chew

Publications and source records attributed to F T Chew.

50 records · Page 3Linked to original sources
PubMed1996

Survival of childhood leukemia in Singapore.

The objective of this study was to evaluate the treatment outcome of children with acute leukemias at a university hospital in Singapore. Between January 1988 and January 1994, 66 children were treated, comprising 13 cases of acute myeloid leukemia (AML) and 53 acute lymphoblastic leukemia (ALL). The 2-year disease-free survival (DFS) was computed according to the Kaplan-Meier method. The results showed that the survival of AML was poor, with a 2-year DFS of only 30%. The major cause of death for AML was leukemia and leukemia-related complications, such as hemorrhage and severe infections. In contrast, a 62% 2-year DFS was achieved for ALL. It was found that marked hepatosplenomegaly (enlarged liver and/or spleen > or = 10 cm below the costal margin) at presentation correlated with a significance shortened survival in our patients with ALL. The major cause for treatment failure in ALL was recurrence of disease. We conclude that the DFS for our patients with ALL at 2 years was fair. The treatment results for AML were poor, but the numbers are too small to make any definite conclusions.

Acute Kidney Injury↗
PubMed1996

Effects of an acaricide on mite allergen levels in the homes of asthmatic children.

Previous study by the current authors has shown that treating homes with D'Allergen, an acaricidal agent, can reduce bronchial hyper-reactivity in asthmatic children with house dust mite allergy. In the present study, the effects of a single D'Allergen treatment on the levels of major dust mite allergens, Der p I and Der f I was evaluated, and the duration of its effectiveness in the environment determined. Twenty randomly selected homes were treated with the acaricide and ten remained untreated. Dust samples were collected from mattresses, upholstered sofas and carpets of these homes before and 1, 2 and 4 months after treatment. The samples were then assayed for Der p I and Der f I allergens using a sandwich enzyme immunoassay. The results showed that D'Allergen was effective in reducing dust mite allergen levels in all three niches by 1.5-22.3 times below baseline values. This effect, however, was only present for 2 months, and the dust mite allergen levels increased to those of the baseline by the fourth month after treatment. These results indicated that repeated applications of the acaricide were required at 2-3 monthly intervals to obtain optimal effectiveness.

Air Pollution, Indoor↗
PubMed1996

Prevalence and severity of asthma, rhinitis, and eczema in Singapore schoolchildren.

This study was part of an international effort to evaluate the epidemiology of asthma and allergic diseases around the world. The aim was to assess the prevalence and severity of these disorders in Singapore schoolchildren. The international study of asthma and allergies in childhood (ISAAC) written questionnaire was administered to 6238 schoolchildren. The respondents were parents of a 6-7 year cohort (n = 2030), and schoolchildren aged 12-15 years (n = 4208). The overall cumulative and 12 month prevalence of wheezing were 22% and 12%, respectively. The prevalence of doctor diagnosed asthma was 20%. Rhinitis was reported by 44% and chronic rashes by 12%. Multiple logistic regression analysis showed that a higher prevalence of wheezing and rhinitis was associated with males, and subjects of higher socioeconomic status (based on type of housing and total family income). More severe asthma related symptoms were present in Malays and Indians than in the Chinese. Allergic disorders are common in Singapore and prevalence is comparable to some populations in the West. Demographic and socioeconomic factors appear to influence the prevalence and severity of these disorders.

Adolescent↗
PubMed1995

Allergens of Bipolaris species.

Skin prick tests done previously revealed a significantly higher percentage of sensitization to an extract of Bipolaris sp. among atopic individuals (34/147, 23.1%) compared to non-atopic individuals. Bipolaris-specific IgE levels were quantified in sera from a representative group of 38 individuals using the Fluorescence Allergosorbent Test (FAST). Result obtained by FAST were found to be comparable to the skin prick test results (r2 = 0.60, p < 0.001 for IgE levels vs wheal sizes; r2 = 0.44, p < 0.001 for IgE levels vs erythema sizes). Characterisation of the extract's allergenic component by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed 28 protein bands with molecular weights (MW) ranging from 11 kDa to above 100 kDa. Immunoblotting with sera of 10 Bipolaris-sensitive (skin prick test, 3 +) individuals showed that Bipolaris spore extract contained at least 4 IgE binding proteins (MW 11-13 kDa, 16-17 kDa, 20-22 kDa and 36 kDa). All 10 sera reacted to the protein at MW 20-22 kDa, 2 sera with MW 11-13 kDa, 3 sera with 16-17 kDa and 6 sera with 36 kDa. This study has thus demonstrated that spores of Bipolaris sp. contain allergenic components which may elicit IgE-mediated reactions.

Allergens↗
PubMed1994

House dust mite allergen levels in a Singapore hospital.

House dust mite allergens constitute one of the most important allergens in house dust. In this study, the levels of two common dust mite allergens, Der p I and Der f I, in a general hospital in Singapore were evaluated. Our results showed that these allergens were detected in 42/74 (or 57%) of the dust samples. Der p I was found to be the predominant allergen detected (p < 0.001). The allergen levels were, however, low with only 1/74 having a Der p I concentration above 2 micrograms g-1 dust. None of the samples had Der f I concentrations above this level. Of the various niches studied (mattresses, pillows, sofas, carpets, blinds and floors), the blinds and floors had the lowest concentration of allergen (p < 0.05). These low levels in the hospital compared to homes were attributed to the vigorous cleaning schedule in the hospital, the use of plastic to encased mattresses and pillows, vinyl covered sofas and vinyl lined floors. These practices may be adopted in the home as a means to reduce mite allergen exposure.

Air Conditioning↗
PubMed1992

Prospective study of the quality of survival of infants with critical fetal reserve detected by antenatal cardiotocography.

From 1981 to 1986 antenatal cardiotocographic monitoring was performed on 9,992 high-risk pregnancies selected from a total obstetrical population of 31,518 patients (31.7%). A critical fetal reserve pattern was detected in 89 patients (0.9%) whose pregnancies resulted in 68 surviving infants, 19 perinatal deaths and 2 sudden infant deaths. Since 47.4% of the infants who died in the perinatal period did so because of a related congenital malformation, such a defect should be excluded in the fetus with critical fetal reserve, by ultrasonography, before delivery (there is usually insufficient time for fetal karyotyping). Sixty-three (92.6%) of the surviving children were assessed at our Growth and Developmental Clinic and disabilities were detected in 16 (25.4%); however, the disability was major in only 5, including 2 children with Down syndrome. The quality of survival of infants born from pregnancies complicated by critical fetal reserve was satisfactory as 60 of 63 children (95.2%) had neither a major disability related to intrauterine hypoxia identified by the cardiotocographic pattern, or had one likely to significantly interfere with their quality of life. Our results suggest that pregnancies can be continued until the cardiotocographic pattern becomes critical in order to gain fetal maturity, without compromise to the fetal brain.

Cardiotocography↗
PubMed1992

Antepartum cardiotocographic surveillance of patients with diminished fetal movements.

Over a 9-year period, 2,601 women had antenatal cardiotocography (CTG) performed after reporting diminished fetal movements. This series represented 5.6% of the total hospital population and 16.1% of those having antenatal CTG performed. The perinatal mortality rate (0.8%) and major fetal malformation rate (2.2%) were lower than in the hospital population (1.1% and 4.5% respectively). The incidence of abnormal CTG tracings was lower in the 1,390 women with diminished movements alone (6.4%) compared with the 1,211 who had additional antenatal complications (10.2%, p less than 0.001). Likewise the incidences of critical fetal reserve CTG and perinatal mortality were significantly lower in the group without additional complications (0.3% and 0.5%) compared with those with additional complications (1.7% and 1.2% respectively). The 24 patients with critical fetal reserve CTG were promptly delivered (19 by Caesarean section) with favourable results in 19, cerebral palsy in 1, and 4 perinatal deaths - 2 of these deaths resulted from intrauterine hypoxia (table 3, Cases 12 and 15). There were 17 perinatal deaths in cases where the CTG was satisfactory (13) or showed reduced reserve (4); 9 of these were unavoidable as a result of major malformations or other lethal conditions. The other 8 deaths resulted from hypoxia, including 4 in pregnancies at or beyond 37 weeks' gestation (table 3, Cases 6-9), illustrating that delivery is warranted in women with diminished fetal movements when conditions are favourable even when the CTG is satisfactory. Cardiotocography is useful in the management of patients with diminished fetal movements.

Cardiotocography↗
PubMed1987

Antepartum cardiotocography--an audit.

Between 1981 and 1986, 9,840 women were monitored by antepartum nonstressed cardiotocography (CTG). A satisfactory fetal reserve pattern was detected in 91%, a reduced reserve pattern in 8% and a critical reserve pattern in 1%. The incidences of fetal growth retardation, Apgar score less than 6 at 1 minute, perinatal mortality and Caesarean section all increased significantly (p less than 0.001) as the degree of cardiotocographic fetal reserve worsened. Intrauterine growth retardation and/or low urinary oestriol excretion was associated with a highly significantly increased incidence of abnormal CTG traces (14.2%, p less than 0.001). A satisfactory fetal reserve pattern on cardiotocography was a reliable predictor of fetal well-being, since after exclusion of lethal malformations, the perinatal mortality rate in those patients monitored within 7 days of delivery was 3/1,000.

Cesarean Section↗
PubMed1985

Nonstressed antepartum cardiotocography in patients undergoing elective cesarean section--fetal outcome.

In a prospective study of 409 patients monitored with nonstressed antepartum cardiotocography and delivered by elective cesarean section, cardiotocography was requested for 170 because of clinical indications. This group had higher incidences of abnormal cardiotocography (p less than 0.001), fetal growth retardation (p less than 0.001) and neonatal deaths (p less than 0.025) than had the group without such requests, suggesting that clinicians effectively selected the high-risk pregnancy for testing of fetal well-being. Cardiotocographic evidence of critical reserve was found in 17 of 170 patients (10%) tested for a clinical indication and in none of the 239 patients in the control group. Patients with abnormal cardiotocography results had significantly higher incidences of cord arterial blood pH less than 7.26 (p less than 0.05) and Apgar scores of less than 6 at 1 minute (p less than 0.001), showing that an abnormal cardiotocogram is indicative of a fetus at risk of having hypoxia.

Apgar Score↗
PubMed1983

Quality of survival of infants with critical fetal reserve detected by antenatal cardiotocography.

During the 8-year period 1973 to 1980, antenatal cardiotocographic monitoring was performed on 3,006 high-risk pregnancies selected from a total obstetric population of 37,856 patients. A critical fetal reserve was detected in 72 patients (2.3%) whose pregnancies resulted in 20 perinatal deaths and 52 infants who survived the neonatal period; 45 of these infants have been assessed at ages ranging from 2 months to 8 years, 9 months. Growth was below the tenth percentile in 25.0% for weight, 23.3% for length, and 22.5% for head circumference at the review examination. Neurological abnormalities were detected in 12 infants but the abnormality was major in only four, including one who has familial interstitial polyneuropathy. The quality of survival of infants delivered of pregnancies complicated by critical fetal reserve is satisfactory; 93.2% had no neurological impairment likely to interfere with quality of life and indeed 13.5% had superior intelligence. Cardiotocographic evidence of critical fetal reserve does not signify that the fetus is doomed; delivery by cesarean section is indicated if the fetus is viable and has no ultrasonic evidence of untreatable major malformation.

Adult↗
PubMedDate not supplied

Proteomic analysis of human tears: defensin expression after ocular surface surgery.

Human tear protein profiles were monitored by surface enhanced laser desorption/ionization-time-of-flight mass spectrometry ProteinChip technology (SELDI-TOF ProteinChip) and liquid chromatography-mass spectrometry (LC-MS). Tears were collected from 21 patients scheduled for surgery to remove an ocular surface neoplasm prior to surgery (day 0) and on days 1, 3, and 30 postoperatively. Using this proteomic approach, we verified that three human alpha-defensins (HNP-1, HNP-2, and HNP-3) were significantly up-regulated in their expression after surgery and that their levels decreased to approximately normal by day 30 by which time healing was complete. Further confirmation of the identity of the alpha-defensins in human tears was made by LC purification, trypsin digestion, and ESI-MS/MS analysis of their tryptic digests. The concentrations of HNP-1 and HNP-2 were determined and shown to be markedly increased after ocular surface surgery. The results of the study suggest that human alpha-defensins HNP-1, HNP-2, and HNP-3 are up-regulated after surgery, and may in addition to their antimicrobial properties have an important role in wound healing.

Amino Acid Sequence↗
PubMedDate not supplied

Utilization of healthcare resources for asthma in Singapore: demographic features and trends.

This study examined the healthcare utilization patterns for asthma in Singapore, a tropical island city-state, between 1986 and 1993. Asthma was ranked fifth among principal conditions with the highest number of discharges in Singapore (2.4 discharges per 1,000 population per annum). Among the 0-14 year-olds, asthma was ranked second, only after accidents and injuries, as the condition with the highest number of discharges (5.2 per 1,000). It was estimated that there were approximately 20,000 accident and emergency (A & E) room visits for asthma per annum (7.0 visits per 1,000 population per annum). There were, however, no significant changes in the number of hospitalized or emergency room cases for asthma over the period of analysis. In the primary healthcare setting, asthma ranked 6th among the leading conditions seen by the general practitioners and government polyclinics (15 visits per 100 population per annum). Among under 15 year olds, asthma (37 visits per 100 age-adjusted population per annum) ranked as the second leading condition behind upper respiratory tract infections. This study has shown that asthma causes a significant amount of morbidity in the Singapore community.

Adolescent↗