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Biomedical subjects

K H Tan

Publications and source records attributed to K H Tan.

At least 55 records · Page 3Linked to original sources
PubMed1999

Confidential enquiry of stillbirths in current obstetric practice.

OBJECTIVE: Confidential panel enquiry into sub-optimal factors relating to stillbirths. METHOD: All 121 stillbirths in KK Women's and Children's Hospital in the years 1995 and 1996 were studied. Three assessors reviewed the case records of each death, and panel consensus was reached regarding sub-optimal antenatal care and factors leading to stillbirths. RESULT: The incidence rate of stillbirth was 4.04 per 1000 deliveries. A total of 76 cases (62.8%) were found to have grade II and III sub-optimal factors in their management. Patients themselves were involved in the sub-optimal management of their own pregnancy in 52.9% of the stillbirths. Primary healthcare givers were involved in 8.3% of all stillbirths, specialist caregivers 12.4% and antenatal care system 4.1%. CONCLUSION: The study has identified sub-optimal antenatal management in over 60% of cases. As patients' factors form the major contribution towards sub-optimal care, management strategy aimed towards improving patients' education and compliance to antenatal care should be a priority.

Adult↗
PubMed1999

Confidential regional enquiry into mature stillbirths and neonatal deaths--a multi-disciplinary peer panel perspective of the perinatal care of 238 deaths.

AIM OF STUDY: To examine the sub-optimal factors relating to the care of stillbirths and neonatal deaths of birthweight 2.5 kg and above. DESIGN: Regional confidential enquiry into stillbirths and neonatal deaths by multi-disciplinary panel. METHODS: All 238 stillbirths and neonatal deaths of 2.5 kg and above in West Midlands Region, UK in the year 1991 were studied. Documents from each death were peer-reviewed by four assessors, one from each of the 4 disciplines, selected randomly from a pool of 24 senior obstetricians, paediatricians, general practitioners and midwives. Panel consensus for each death was reached to identify relevant factors related to sub-optimal care which might have prevented or would reasonably be expected to prevent an adverse outcome (Grades II & III sub-optimal care). RESULTS: A total of 149 (62.7%) deaths were considered by the panel to have grade II or III factors. Of these, 151 (68.9%) were found in the antepartum period, 44 (20.1%) in the intrapartum period and 24 (11.0%) in the postpartum period. The majority (78.1%) of these factors involved clinical practice of care providers. Factors related to patient/family, equipment and staffing constituted 19.6%, 1.4% and 0.9% respectively. Important sub-optimal factors identified were lack of appreciation of antenatal and intrapartum risks factors (17.8%), the failure of proper interpretation and management of antepartum and intrapartum cardiotocography (12.8%), failure of adherence to accepted practice or standard care (12.8%), inadequate skills in neonatal resuscitation (4.5%) and adverse patient-related factors (19.6%). CONCLUSION: Substantial scope exists for confidential multi-disciplinary peer review audit of current obstetric and neonatal care in the region in formulating a strategy to reduce perinatal mortality.

Adolescent↗
PubMed1999

Dissolution of thrombus formed during direct coronary angioplasty with a single 10 mg intracoronary bolus dose of abciximab.

Direct coronary angioplasty with stent implantation is an effective treatment for acute myocardial infarction. The use of adjunctive abciximab, a platelet glycoprotein IIb/IIIa receptor antagonist is expensive. We report on three cases of direct coronary angioplasty complicated by extensive thrombus formation that were successfully treated with attenuated dosing of abciximab via the intracoronary route. All patients presented with acute myocardial infarction complicated by cardiogenic shock or eminent cardiogenic shock. Abciximab was administered after balloon dilatation when extensive thrombus formation was noted and persisted despite repeated inflations. In all three patients a single 10 mg vial of intracoronary abciximab was administered, resulting in complete dissolution of thrombus, allowing successful deployment of stents. Thus, a single 10 mg intracoronary bolus dose of abciximab may be sufficient to achieve high local concentrations of antiplatelet activity. This facilitates thrombus dissolution and allows the safe deployment of a stent to normalise intracoronary rheology.

Abciximab↗
PubMed1999

Antenatal HIV screening--knowledge, attitudes and practices of obstetricians in KKH.

AIM OF STUDY: To determine the knowledge, attitudes and practices of obstetricians with regards to HIV screening in pregnant women. METHOD: This is a cross-sectional study based on a questionnaire survey of all obstetricians in KKH from January to August 1997. MAIN OUTCOME MEASURES: Obstetricians' knowledge and beliefs of HIV epidemiology and HIV perinatal transmission, and attitudes and practices with regards to antenatal HIV screening. RESULTS: Forty-one (77.4%) obstetricians responded to the survey. At the time of the survey, only 43.9% of the respondents had offered the HIV serology test to their patients with only 17.1% and 19.5% providing pre-test and post-test counselling respectively. Seventy-eight percent of them were aware of reports that zidovudine could reduce the vertical HIV transmission rate. All the respondents felt that HIV testing should be performed in pregnant women. The majority (70.7%) felt that antenatal HIV testing should be voluntary rather than mandatory and 56.1% felt that the patients' civil rights and confidentiality could be more assured if HIV testing is voluntary than if it was mandatory. Most respondents (56.1%) felt that antenatal HIV screening should be universally offered rather than targeted to those with risk factors. Most obstetricians did not feel comfortable (58.5%) or competent (80.5%) to manage HIV infection in pregnancy. Those who felt competent were more likely to feel comfortable, more likely to have provided HIV test in the clinic, and less likely to opt out of caring for an HIV-infected patient. CONCLUSION: The majority of the surveyed obstetricians would support a program of voluntary antenatal HIV screening that is universally offered to all pregnant women. The feelings of discomfort and incompetence of the obstetricians towards caring for an HIV-infected pregnant woman need to be addressed further. There is a need for continuing medical education to help obstetricians keep abreast with the advances in HIV screening and its management.

AIDS Serodiagnosis↗
PubMed1999

[Establishment of studying system cloned vernalization-putative cDNA clone by means of differential display PCR].

Differential display PCR has been developed as a tool detecting and characterizing specially expressed gene in eukaryotic cells recently. In this paper, a studying system was established which applied the novel approach of differential display PCR to clone vernalization-related cDNA clone. Here methodological details were provided which included the purification of total RNA, removal of contaminated DNA, reverse transcription of cDNAs, parameters of PCR, electrophoresis of amplified cDNAs, recovery and reamplification of cDNAs. It was also identified a vernalization-putative cDNA clone (VPC) of VPC28 which was only expressed at the key stage of vernalization for 20 d in winter wheat. These results moreover made it readily applicable to a broad spectrum of similar studies.

Cloning, Molecular↗
PubMed1998

Induction of astrocyte metallothioneins (MTs) by zinc confers resistance against the acute cytotoxic effects of methylmercury on cell swelling, Na+ uptake, and K+ release.

Metallothionein (MT) proteins play an important role in the detoxification of heavy metals. Since methylmercury (MeHg) preferentially accumulates in astrocytes, we investigated the ability of the astrocyte-specific MT isoform, MT-I, to attenuate MeHg-induced cytotoxicity. Increased astrocytic MT expression was achieved by 24-h pretreatment of neonatal rat primary astrocyte cultures with 100 microM zinc (ZnSO4). Subsequently, the astrocytes were treated with MeHg (10 microM), and its toxic effects on cell volume, Na+ uptake, and K+ release were investigated and compared to cells treated with or without MeHg, but in the absence of Zn pretreatment. Pretreatment of astrocytes with Zn was associated with a 2.9-fold increase in MT protein levels (P<0.02), and a 5.6-fold increase in MT mRNA levels (p<0.002) compared to control astrocytes. Astrocytes expressing increased MT protein levels were resistant to MeHg-induced swelling. In isotonic buffer the effect of MeHg on swelling was abolished (p<0.01) by 24-h Zn pretreatment, in such a way that volume profiles in these cells did not differ from controls. Zn-induced increased expression of MTs was also associated with significant attenuation of astrocytic Na+ uptake (p<0.01) and Rb+ (a marker for K+) release (p<0.001) in response to treatment with MeHg. These results demonstrate (1) that astrocytes can be induced to express high levels of MT proteins by pretreatment with Zn, and (2) that Zn confers resistance against the acute effect of MeHg on astrocytic swelling and the associated changes in ion (Na+ and K+) transport. Taken together, the data suggest that astrocytic MT induction offers effective cellular adaptation to MeHg cytotoxicity.

Animals↗
PubMed1998

Dimethyl sulfoxide, but not acidosis-induced metallothionein mRNA expression in neonatal rat primary astrocyte cultures is inhibited by the bioflavonoid, quercetin.

Metallothionein (MT) mRNA levels were analyzed following exposure of neonatal rat primary astrocyte cultures to physiologic pH (7.4), acidosis (pH 6.5 and 6.0), and dimethyl sulfoxide (DMSO). Treatments were carried out both in the presence and absence of the bioflavonoid, quercetin. Total RNA was probed on northern blots with [alpha32P]dCTP-labeled synthetic cDNA probes specific for rat MT isoform mRNAs. MT-I and MT-II mRNA levels in astrocytes exposed to pH 6.5 or pH 6.0 were increased compared to controls (pH 7.4). Treatment with DMSO in the presence and absence of acidosis, also increased MT-I and MT-II mRNA levels compared to controls (pH 7.4). The DMSO-induced increase in MT mRNA expression was reversed by treatment of astrocytes with quercetin, such that MT-I and MT-II mRNA levels in DMSO plus quercetin-treated astrocytes were indistinguishable from mRNA levels in their respective controls at pH 7.4, pH 6.5, and pH 6.0. These findings suggest that both acidosis and DMSO exposure are associated with increased astrocytic MT synthesis at the mRNA level, and that quercetin, effectively blocks MT mRNA induction by DMSO.

Acidosis↗
PubMed1998

Bail-out stenting of the unprotected left main stem.

Two cases of life-threatening left main stem (LMS) complications during routine cardiac catheterization were successfully treated with intracoronary stenting prior to successful emergency bypass surgery. Intracoronary stenting is of value in stabilising patients before emergency bypass surgery and can save lives in LMS complications.

Aged↗
PubMed1998

Validation of an oscillometric electronic sphygmomanometer in an obstetric population.

Use of an automated electronic sphygmomanometer will allow us to minimize the errors inherent in mercury sphygmomanometry. We conducted this validation according to the 1990 protocol of the British Hypertensive Society. We recruited 87 subjects from the antenatal population of Kandang Kerbau Hospital and took three sequential readings using simultaneously both manual and electronic sphygmomanometry. A total of 261 readings from either method were thus collected and the results analyzed to compare the accuracy of electronically read blood pressure with that assessed manually. We found that 89.9% of the electronically read pressures differed from the manually read pressures by 5 mm Hg or less and 98.9% of the electronic readings differed from manual readings by 10 mm Hg or less; only 0.4% of readings had a difference of more than 15 mm Hg. The accuracy of the device was not affected either by the blood pressure or the arm circumference.

Adult↗
PubMed1998

Ureteral injuries in an obstetric and gynaecology teaching hospital.

Between November 1994 to May 1996, there was a total of eight ureteric injuries out of 2495 major gynaecologic operations and one ureteric injury out of 4146 caesarean sections at the Kandang Kerbau Hospital, giving the incidence to be 0.3% and 0.02% respectively. Antecedent operations were four abdominal hysterectomies, two Werthiem's hysterectomies, one laparoscopic-assisted vaginal hysterectomy and one caesarean section. All operations were performed by qualified specialists. Three patients had previous abdominal operations and five patients had procedures complicated by dense adhesions. Only one injury was detected intraoperatively and the rest presented with uretero-vaginal fistula. One presented with immediate postoperative anuria. The average time interval for diagnosis ranged between one day and twenty-three days (average 10.7 days). The commonest damage was transection of the ureter. Double J stents were used in all repairs with two cases requiring reimplantation with psoas hitch, and two cases of ureteroneocystostomies and one case of primary reanastomosis. There were no mortality in our series.

Adult↗
PubMed1997

Localization of genes encoding two human one-domain members of the AAA family: PSMC5 (the thyroid hormone receptor-interacting protein, TRIP1) and PSMC3 (the Tat-binding protein, TBP1).

The eukaryotic genome contains a putative AT-Pase gene family that encodes proteins with one or two highly conserved domain(s) of approximately 230 amino acids. These proteins have diverse cellular functions and mutation in at least one member of the family has been associated with human disease, while mutations in other family members are known to cause cell cycle defects in yeast. Therefore it is of interest to map more family members and so we have localized PSMC5 (the thyroid hormone receptor-interacting protein, TRIP1) and PSMC3 (the Tat-binding protein, TBP1) to chromosomes 17q24-q25 and 11p12-p13, respectively. We also present the map position of a probable PSMC3 processed pseudogene locus on chromosome 9p.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1997

Non-atherosclerotic coronary artery aneurysms: two case reports.

Non-atherosclerotic isolated coronary artery aneurysm is not common. Two cases of non-atherosclerotic isolated coronary artery aneurysm, with similar presentations but different management strategies were presented. The patients were well four and six years later, respectively. The definition, incidence, causes, presentation, complications, investigations, management, and prognosis of coronary artery aneurysms are discussed. The difficulties of determining pathogenesis and different management strategies are highlighted. An isolated coronary artery aneurysm should be managed on its merits.

Acute Disease↗
PubMed1997

Optimising management of stillbirths in modern Singapore.

OBJECTIVE: To conduct a critical analysis of stillbirths in Kandang Kerbau Hospital with emphasis on epidemiological factors, related causes and investigation strategies. DESIGN: A prospective study. SETTING: Kandang Kerbau Hospital. PATIENTS: Case records containing antenatal and post-partum details of all 136 stillbirths were obtained from the medical records office and reviewed by 3 obstetricians. Epidemiological data, antenatal history, intrapartum progress, post-partum investigation, post-mortem findings (where applicable) were reviewed and recorded. RESULTS: The incidence of stillbirths was 4.48/ 1,000 in 1994. 73.1% of the stillbirths were macerated. Significantly higher stillbirth rates were noted in the Malays and unbooked or late booking cases. The causes of stillbirths were unexplained in 29.4%. Fetal anomalies constituted 18.4%, followed by asphyxia, abruptio, and cord accidents. Maternal obstetrical problems contributed to the rest. CONCLUSION: A comprehensive management strategy to reduce stillbirths include community and patient education, early or shared antenatal care, careful prenatal surveillance, optimum investigations as well as a careful audit with adequate bereavement and counselling.

Female↗
PubMed1996

Congenital anterior abdominal wall defects in England and Wales 1987-93: retrospective analysis of OPCS data.

OBJECTIVES: Analysis of incidence and characteristics of congenital abdominal wall defects, with special reference to the differences between the incidence of gastroschisis and exomphalos (omphalocele). DESIGN: Retrospective analysis using data from the Office of Population Censuses and Surveys (recoded to differentiate exomphalos and gastroschisis) and the National Congenital Malformation Notification Scheme. SETTING: England and Wales, 1987 to 1993. RESULTS: 1043 congenital anterior abdominal wall defects were notified within the seven year study period. Of these, 539 were classified as gastroschisis, 448 as exomphalos, 19 as "prune belly syndrome," and 37 as "unclassified." Gastroschisis doubled in incidence from 0.65 in 1987 to 1.35 per 10,000 total births in 1991, with little further change; the incidence of exomphalos decreased from 1.13 to 0.77 per 10000 births. The overall incidence of notified congenital abdominal wall defects was 2.15 per 10000 total births. Gastroschisis was associated with a lower overall maternal age than exomphalos and with a significantly lower proportion of additional reported congenital malformations (5.0%) than in the cohort with exomphalos (27.4%) (odds ratio 0.14, 95% confidence interval 0.09 to 0.22; P < 0.001). The sex ratio of the two cohorts was the same. The incidence of gastroschisis and exomphalos was higher in the northern regions of England than in the south east of the country. CONCLUSIONS: The national congenital malformation notification system showed an increasing trend in the incidence of fetuses born with gastroschisis and a progressive decreasing incidence of exomphalos in England and Wales between 1987 and 1993. Although the reasons for this are likely to be multifactorial, a true differential change seems likely. The observed increase in incidence of gastroschisis relative to exomphalos and the differentiation in maternal age have implications for resource management within the NHS and warrant further epidemiological monitoring. Regional differences may be due to a dietary or environmental factor, which requires further study.

Abdominal Muscles↗