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Biomedical subjects

K L Tan

Publications and source records attributed to K L Tan.

At least 91 records · Page 5Linked to original sources
PubMed1989

Management of neonatal jaundice.

Neonatal jaundice is the commonest complication among newborn infants in Singapore. Treatment is only required when the jaundice becomes severe. The trans-cutaneous bilirubinometer is useful in screening for neonatal jaundice; it is fairly reliable at levels less than or equal to 200 mumol/l in fullterm babies. Phototherapy is the commonest form of treatment and is effective in almost all cases if high intensity phototherapy is also used. Exchange transfusion is now only rarely used in view of its known complications and relatively high mortality rate.

Exchange Transfusion, Whole Blood↗
PubMed1989

Clinical experience with phototherapy.

Clinical experience with phototherapy in 3,999 infants with non-haemolytic hyperbilirubinaemia and 427 infants with hyperbilirubinaemia associated with G6PD deficiency is presented. For non-haemolytic hyperbilirubinaemia, phototherapy was extremely effective in extremely preterm infants with very low birth weight (gestation less than or equal to 32 weeks, birth weight less than or equal to 1,500 gm) and least effective in full term infants with very low birth weight (gestation greater than 37 weeks, birth weight less than or equal to 1,500 gm) and large preterm infants (gestation less than 37 weeks, birth weight greater than 2,270 gm). The failure rate of phototherapy for non-haemolytic hyperbilirubinemia was only 2.00/1,000 infants. The bilirubin rebound was usually mild; repeat phototherapy was required in only 30 infants (7.50/1,000) with the response to the second exposure comparable to that of the first. No infant required a third exposure. Phototherapy was effective in reducing bilirubin levels in hyperbilirubinaemia associated with G6PD deficiency, the effectiveness being, however, less than in babies with non-haemolytic hyperbilirubinaemia (G6PD normal status). There was no failure in this group of babies. Only a small proportion of infants required a second exposure (4.68/1,000). All the infants tolerated phototherapy well with none developing any illness that could be attributed to the exposure. This clinical experience demonstrates that phototherapy is effective and safe for the treatment of non-haemolytic hyperbilirubinaemia or hyperbilirubinaemia associated with G6PD deficiency.

Bilirubin↗
PubMed1989

Unusual presentation: testicular seminoma.

A case of seminoma is described in a patient with HIV infection. The tumor presented atypically with no lymphocytic infiltrates within the stroma. HIV infection has been reported to be associated with an increased incidence of Kaposi's sarcoma, non-Hodgkin's lymphomas, oropharyngeal carcinoma and pancreatic carcinoma.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Haematolytic disease due to ABO incompatibility: incidence and value of screening in an Asian population.

The population in Singapore is predominantly Asian, with Chinese forming the major ethnic group. The incidence of haemolytic disease of the newborn (HDN) due to Rh incompatibility is very low. The true incidence of HDN due to ABO incompatibility is unknown. Early discharge is practised in Singapore making it important to predict severe HDN due to ABO incompatibility as this would constitute the main cause of haemolysis next to G6PD deficiency. One thousand, six hundred and eight baby-maternal pairs were typed for ABO, Rh, and tested for direct Coombs' test, maternal titre, cord bilirubin and haptoglobin levels. Two hundred and fifty-one were found to be ABO incompatible, with 141 group A and 110 group B babies. The incidence of HDN due to ABO incompatibility was 3.7% of all group O mothers. Coombs' test, maternal antibody titre, cord bilirubin and haptoglobin levels were of low predictive value for severe HDN due to ABO incompatibility. The data further support the notion that it is not cost effective to screen for ABO incompatibility.

ABO Blood-Group System↗
PubMed1988

A comparative study on schizophrenia diagnosed by ICD-9 and DSM-III: course, family history and stability of diagnosis.

Data from the Taipei Center of the International Pilot Study of Schizophrenia were reanalyzed using the ICD-9 and DSM-III diagnoses at 7-year follow-up. Patients diagnosed as schizophrenic according to DSM-III were shown to be a more homogeneous group in terms of their clinical manifestations, social functions and family psychiatric history than those defined as schizophrenic by ICD-9. The discordant cases of ICD-9 schizophrenia and DSM-III affective disorders were found to be different from the concordant schizophrenic group, but similar to the concordant group of affective disorders diagnosed by ICD-9 and DSM-III. Thirty-five per cent of mood-incongruent psychotic major depressive disorders defined by DSM-III at initial evaluation were diagnosed as schizophrenia at 7-year follow-up.

Follow-Up Studies↗
PubMed1988

Transcutaneous bilirubinometry in preterm very low birthweight infants.

Transcutaneous bilirubinometry using the Minolta Airshield TcB was performed on 40 preterm VLBW Chinese infants during the first 7 days of life; altogether 614 observations were made on the forehead and sternum, respectively. A positive correlation between the TcB index and plasma bilirubin concentration was obtained on the forehead and sternum. Positive plasma bilirubin-TcB index correlations were also observed for each individual day. The plasma bilirubin-TcB index (forehead) regressions were fairly similar for the individual days and the combined overall regression except for 2 days (days 5 and 7). A slight improvement was observed when only bilirubin concentrations less than or equal to 200 mumol/l were evaluated. The intercepts were however different for individual days requiring correction factors to the combined overall regression intercept if the regression is to be used for the respective days. However, the plasma bilirubin-TcB index (sternum) regression for the individual days were significantly different one from another, and from the overall combined plasma bilirubin-TcB index (sternum) regression. This significant difference was still observed when only plasma bilirubin concentrations less than or equal to 200 mumol/l were evaluated. Hence, transcutaneous bilirubinometry has major limitations in preterm VLBW infants.

Bilirubin↗
PubMed1988

Efficacy of hepatitis B immunisation.

Hepatitis B virus (HBV) infection is endemic to Singapore, the carrier rate being highest among the Chinese. It is the cause of significant morbidity and mortality. The prevention of this condition is therefore an important objective. Plasma derived vaccines have been shown to be effective in the prevention of perinatal as well as horizontal spread of HBV. However, the high cost of production together with deep-seated, though unfounded fears of the possibility of transmission of other viruses has limited its use. The advent of recombinant yeast vaccine is therefore an important event since the unfounded fears can now be laid to rest, and the cost of immunisation should eventually decrease as production increases. The efficacy of recombinant yeast vaccine has been found to be comparable to that of plasma derived vaccine.

Hepatitis B↗
PubMed1988

Incidence and epidemiology of cleft lip/palate in Singapore.

This is an on-going study monitoring congenital malformations in all babies delivered in the Kandang Kerbau Hospital, Singapore. Cleft lip and cleft palate as well as a combination of both are among those conditions closely monitored. Up till December 1987, 24 months after the study commenced, a total of 30,411 newborn infants have been screened, out of which 53 infants presented with one of these conditions, an incidence of 0.17% (one per 574 births). There were 26 males and 27 females. During this period, 15,564 males and 14,847 females were delivered; incidence in males was 0.17% and females 0.18%. The incidence in Chinese was 0.20%, Malays 0.14% and Indians 0.09%. Of the 53 cases, 11 (20.7%) have isolated cleft lip, 18 (34.0%) isolated cleft palate and 24 (45.3%) both cleft lip and palate combined. Comparison with a set of controls matched with regards to place and time of delivery, maternal age, maternal parity and ethnic group was made. Analysis of the study and control groups demonstrated that early menarche, regular menstrual periods, and ingestion of traditional medicine were significantly associated with facial clefts.

Cleft Lip↗
PubMed1987

Neonatal jaundice in 'healthy' very low birthweight infants.

The daily bilirubin levels during the first week of life in 94 premature very low birthweight (VLBW, less than 1500 g) relatively 'healthy' infants were determined. Mean daily bilirubin values peaked on the fourth day of life at 188.1 mumol/l (s.e.m. = 5.3). Twenty-eight infants developed hyperbilirubinaemia (bilirubin greater than 260 mumol/l), at which time they were exposed to phototherapy. When individual peak bilirubin values were evaluated, the overall peak value was 213.9 mumol/l (s.e.m. = 5.1) occurring at 4.81 days (s.e.m. = 0.11), although the value is most likely an underestimate, since the 28 pre-phototherapy values were not truly peak values. Seventy-six (81%) infants experienced bilirubin levels greater than 170 mumol/l. The method of delivery apparently had no impact on the bilirubin levels. All the infants remained well and progressed satisfactorily. 'Healthy' VLBW infants experience a much greater incidence and severity of neonatal jaundice than mature infants with the same clinical status.

Age Factors↗
PubMed1987

alpha-Fetoprotein levels in fullterm and very low birthweight infants.

Plasma alpha-fetoprotein (alpha-FP) levels were determined in fullterm and very low birthweight (VLBW) infants in the first week of life and serially in a cohort of VLBW infants for the first 24 weeks after delivery. A rapid decline in alpha-FP levels was observed in both the fullterm and VLBW infants initially. Beyond 2 weeks of age, there was a gradual, linear decline until 6 weeks, followed by a more rapid period of decline from 6 to 16 weeks. The decline in the ensuing weeks demonstrated an asymptotic pattern. The half-life of alpha-FP was 7.5 days in the first week of life in both fullterm and preterm infants, 28.7 days from 2 to 6 weeks of life and 11.9 days from 6 to 16 weeks of life in VLBW infants.

Female↗
PubMed1987

Blood pressure in full-term healthy neonates.

The blood pressure (BP) of 46 healthy full-term infants was studied in the first 6 consecutive days of life using the Dinamap. The BP gradually increased with age to peak at 4 or 5 days of age before subsiding a little at 6 days. There was a significant increase in BP values from the second to the third day of life in both the systolic and diastolic pressures during the waking state but not during sleep. The waking and sleeping BP, almost identical in the first day, diverged with increasing age, although no significant difference could be demonstrated between the respective values during the 6 days of study in systolic, diastolic, or mean arterial pressure. BP values obtained in the left and right upper limbs and right lower limb were similar for the respective days, with minor variations in pattern. The waking and sleeping heart rate, identical on the first day, also diverged with increase in age but again no significant difference was observed on the first 6 days. There was no correlation between the BP and heart rate on any of the 6 days. However, a positive correlation between the daily mean systolic pressure and heart rate only in the waking state was observed over the course of the 6-day study period.

Age Factors↗
PubMed1987

Intra-uterine infections.

The incidence of intrauterine infections during pregnancy is estimated to be about 14% when laboratory methods of detection are used. The commonest infections are cytomegalovirus infection, congenital rubella followed by herpes simplex. Hepatitis B virus infection occurs fairly frequently in this region of the world. Congenital syphilis, now highly treatable, is largely under control. Preventive measures are necessary since the lesions caused by some intrauterine infections are permanent and damaging. Immunisation against hepatitis and rubella is effective. Most of these infections are spread by close intimate contact. Hence, avoidance of such contact with persons with suspected infections would be wise during pregnancy.

Cytomegalovirus Infections↗
PubMed1986

Efficacy of phototherapy in non-haemolytic hyperbilirubinaemia.

Clinical experience of phototherapy for non-haemolytic hyperbilirubinaemia in 3999 infants in Kandang Kerbau Hospital, Singapore, is documented. Phototherapy was most effective in extremely preterm infants with very low birth weight (gestation less than or equal to 32 weeks, birth weight less than or equal to 1500 g) and least effective in full term infants with very low birth weight (gestation greater than or equal to 37 weeks, birth weight less than or equal to 1500 g) and large preterm infants (gestation less than 37 weeks, birth weight greater than 2270 g). Overall, phototherapy was effective in almost all the infants, with a failure rate of only 2.00/1000 infants. No characteristic features common to all the failures could be detected. The bilirubin rebound was usually mild; repeat phototherapy was required in only 30 infants (7.50/1000), with the response to the second exposure comparable to that to the first. No infant required a third exposure. All the infants tolerated phototherapy well, none developing any illness that could be attributed to the treatment. This clinical experience shows that phototherapy for the treatment of nonhaemolytic hyperbilirubinaemia is effective and safe.

Bilirubin↗
PubMed1986

Evaluation of a low dose of hepatitis B vaccine given within a childhood immunisation programme in Singapore.

The feasibility of introducing low dose (5 micrograms) hepatitis B (HB) virus vaccination at birth and again 1 and 2 months later as part of an existing primary immunisation programme of childhood, was assessed in 662 healthy newborn Singapore children. The vaccine (B-Hepavac, Menck, Sharp and Dohme) was given to three neonatal groups: those born to HB surface antigen (sAg)-negative mothers, HBsAg-positive/HBeAg-positive mothers and HBsAg-positive/HBeAg-negative mothers. A dose of 5 micrograms was compared in a randomised study with the more usual 10 micrograms dose given at the same intervals. Neonates born to HBsAg-positive/HBeAg-positive mothers were also given hepatitis B immunoglobulin (HBIg) at birth. The 5 microgram dose of vaccine was as immunogenic as the 10 microgram dose in all three groups of children studied. At 1 year, anti-HBsAg seroconversion among infants of antigen-negative mothers was 95.8% for the 5 microgram dose and 91.9% for the 10 microgram dose. Suppression of anti-HBsAg formation was not seen even when maternal anti-HBsAg was present or HBIg given. Among infants born to HBsAg-positive/HBeAg-positive mothers, passive plus active immunisation was 100% protective at doses of 5 micrograms and 10 micrograms vaccine in the newborns who were HBsAg-negative at 24 h. Seroconversion after both the 5 and 10 microgram doses of vaccine was reduced, however, to 88% in each group of infants who were already HBsAg-positive at 24 h of age. Overall, passive plus active immunisation as well as HB vaccine alone (5 micrograms dose), given within the existing but expanded primary immunisation programme of childhood, was effective in preventing infection and the chronic carrier state in newborns exposed to risk of HB virus infection during infancy.

Carrier State↗
PubMed1985

Maternal-child hepatitis B virus transmission in Singapore.

A study of maternal-infant transmission of hepatitis B virus (HBV) was conducted in Singapore between June 1980 and June 1982. HBsAg carrier rate was highest among Chinese (6.2%) followed by Malay (2.3%) and Indian (0.6%) mothers. The presence of HBeAg in maternal sera correlated well with high titre HBsAg (p = 7.34 X 10(-5)). Overall HBV transmission occurred in 27/56 (48.2%) infants from carrier mothers. The majority of the transmission was perinatal. There was a very strong correlation between transmission and HBeAg status of the mother (p = 1.85 X 10(-9); odds ratio = 68.44) and to a lesser extent with high titre HBsAg (p = 0.002; odds ratio = 6.38). A strong negative correlation was seen between transmission and anti-HBeAg (p = 8.19 X 10(-7); odds ratio = 0.04). At one year 19 (70.4%) infants were still HBsAg positive while seven (25.9%) lost the antigenemia and acquired anti-HBsAg and one developed HBsAg after one year. It could be calculated that perinatal HBV transmission contributed about 18% to the total pool of HBsAg positive infants of one year of age.

Carrier State↗
PubMed1985

Comparison of tears and lacrimal gland fluid in the rabbit and guinea pig.

The excretory duct of the lacrimal gland of rabbits and guinea pigs was cannulated in situ for collection of pure lacrimal gland fluid, not contaminated by secretions from the Harderian gland or contributions of desquamating cells of the conjunctival and corneal epithelium. Tears as well as lacrimal gland fluid of both species showed a species-specific and molecular weight-dependent pattern after sodium dodecylsulphate-polyacrylamide (SDS-PAA) gradient slab gel electrophoresis. The most striking difference in both species was a protein corresponding to serum albumin present in tears and almost lacking in lacrimal gland fluid. Likewise, a variety of enzymes, total protein and PGE2 were measured in tears and lacrimal gland fluid. For rabbit tears the lacrimal gland is the primary tissue source of lysozyme (LZM), beta-hexosaminidase (beta-hex), angiotensin-converting enzyme (ACE), plasminogen activator (PA) and total protein, while lactate dehydrogenase (LDH) and the greater part of prostaglandin E2 (PGE2) are present in rabbit tears mainly as products from other ocular tissue sources. In guinea pig tears peroxidase (POD), ACE, PA and less PGE2 are exceted by the lacrimal gland, amylase (AMY), LDH and a substantial amount of PGE2 are added to the guinea pig tears by other ocular tissue sources. Beta-hex and total protein are released from the lacrimal gland and from other ocular tissue sources as well.

Animals↗