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Tsoi WF, Tan CT, Kok LP. Fluoxetine in the treatment of depression in Asian (Chinese and Indian) patients in Singapore. Singapore Med J 1995; 36:397-9. [PMID: 8919155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of this paper is to study the efficacy and side-effects of fluoxetine. Fluoxetine is a specific serotonin reuptake inhibitor. Nineteen Asian (Chinese and Indian) patients who satisfied the DSM-3R criteria for major depressive episode were treated with fluoxetine 20 mg daily for 12 weeks. They were monitored two weekly. The results showed that during the period of treatment there was significant improvement in depressive symptoms and no serious side-effects. There were no significant changes in weight, temperature, blood pressure and pulse rate throughout the 12 weeks. This study showed that fluoxetine was well-tolerated and relieved the symptoms of depression effectively. Most of the results are supported by other studies.
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Ng WK, Tan CT, George J, Lee MK, Loh TG. Moyamoya disease in Malaysia: two documented cases. THE MEDICAL JOURNAL OF MALAYSIA 1995; 50:186-188. [PMID: 7565194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Moyamoya disease is a rare cause of young strokes. The definitive diagnosis of moyamayo disease is made by cerebral angiography. We report two cases of moyamoya disease in Malaysia.
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Boivin JF, Hutchison GB, Zauber AG, Bernstein L, Davis FG, Michel RP, Zanke B, Tan CT, Fuller LM, Mauch P. Incidence of second cancers in patients treated for Hodgkin's disease. J Natl Cancer Inst 1995; 87:732-41. [PMID: 7563150 DOI: 10.1093/jnci/87.10.732] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Numerous studies of treatment for Hodgkin's disease have demonstrated large increases in the incidence of leukemia in the early years following chemotherapy, although the duration of effect and the specific agents involved are not well understood. Also, some, but not all, studies have indicated that the incidence of certain solid tumors increases following treatment for Hodgkin's disease. PURPOSE We studied the association between treatment for Hodgkin's disease and the incidence of second cancers. METHODS We conducted a study within a cohort that included 10,472 patients from 14 cancer centers in the United States and Canada who were first diagnosed as having Hodgkin's disease at some point from 1940 through 1987. Discounting the 1st year after diagnosis, the average length of follow-up was 7.1 years per subject. RESULTS We observed 122 leukemias and 438 solid tumors. The relative risk (RR) of leukemia following chemotherapy, compared with no chemotherapy, was 14 (95% confidence interval [CI] = 5.6-35). Increased risks of leukemia were observed after treatment with chlorambucil (RR = 2.0; 95% CI = 1.1-3.6), procarbazine (RR = 4.9; 95% CI = 2.6-9.1), vinblastine (RR = 1.7; 95% CI = 1.1-2.8), and a group of rarely used drugs that included methotrexate, vindesine, etoposide, and 22 others (RR = 3.8; 95% CI = 1.9-7.4). RRs were also estimated for various combinations of drugs, including MOPP (mechlorethamine, vincristine, procarbazine, and prednisone) (RR = 5.9; 95% CI = 2.9-12) and ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) (RR = 1.5; 95% CI = 0.7-3.4). The RR of leukemia associated with splenectomy was 1.6 (95% CI = 1.0-2.5). The RR of solid tumors following chemotherapy was 1.4 (95% CI = 1.1-1.8). For the group of rarely used drugs, the RR of solid tumors was 3.1 (95% CI = 1.7-5.8). Chemotherapy was associated with an increased risk of cancers of the bones, joints, articular cartilage, and soft tissues (RR = 6.0; 95% CI = 1.7-20), and cancers of the female genital system (RR = 1.8; 95% CI = 1.1-3.2). In patients followed for 10 or more years after radiotherapy, increased risks were found for cancers of the respiratory system and intrathoracic organs (RR = 2.7; 95% CI = 1.1-6.8) and for cancers of the female genital system (RR = 2.4; 95% CI = 1.1-5.4). CONCLUSIONS Procarbazine, chlorambucil, and vinblastine are associated with increased leukemia risk. Combination drug regimens have leukemogenic effects estimated as the product of RRs for individual drugs. Chemotherapy and radiotherapy increase the risk of selected solid tumors, and the effect of chemotherapy on solid tumor risk is weaker than the leukemogenic effect. IMPLICATIONS Without doubt, the benefits of treatment of Hodgkin's disease outweigh the risk of a subsequent malignancy, but data on the carcinogenic effects of radiation and drugs beyond 10 years after treatment continue to be sparse, and future analyses should be directed at long-term survivors.
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Chye ML, Liu CM, Tan CT. A cDNA clone encoding Brassica calmodulin. PLANT MOLECULAR BIOLOGY 1995; 27:419-423. [PMID: 7888630 DOI: 10.1007/bf00020195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A 834 bp cDNA encoding calmodulin (CaM) has been isolated from Brassica juncea. On Northern analysis this cDNA hybridises this cDNA to mRNAs of about 0.9 kb in leaf, silique and peduncle. Genomic Southern analysis indicates the presence of a CaM multigene family in Brassica juncea. Comparison of the predicted amino acid sequence of Brassica CaM with that of Arabidopsis CaM ACaM-2 and ACaM-3 showed 100% homology, which is not unusual, since both plants belong to the family Cruciferae. In situ hybridisation studies on Brassica seedlings using a digoxigenin-labelled RNA probe showed that high levels of CaM mRNA were detected in the leaf primordia and the shoot apical meristem, and to a lesser degree, in the zone of root elongation of the root tip. The occurrence of a higher rate of cell division and growth in these regions than its surrounding tissue may possibly be related to higher levels of CaM mRNA.
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Ng WK, Tan CT. Paroxysmal cerebellar ataxia: use of phenytoin as a provocation test. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1994; 24:583. [PMID: 7848171 DOI: 10.1111/j.1445-5994.1994.tb01770.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Tan CT, Wollner N, Trippett T, Goker E, Tong WP, Kheradpour A, Meyers PA, VanSyckle KM, Guarino L, Elisseyeff Y. Pharmacologic-guided trial of sequential methotrexate and thioguanine in children with advanced malignancies. J Clin Oncol 1994; 12:1955-62. [PMID: 7521908 DOI: 10.1200/jco.1994.12.9.1955] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
PURPOSE Based on in vitro studies that have shown synergistic effects of sequential administration of methotrexate (MTX) and thioguanine (6-TG), we conducted a pharmacologically guided trial of sequential MTX and 6-TG to determine the following: (1) the maximum-tolerated dose (MTD) of 6-TG; (2) the nature of the dose-limiting toxicity; and (3) the modulation effect of MTX on 6-TG given by this sequence and schedule. PATIENTS AND METHODS Thirty-one children with advanced malignancies (acute leukemia, n = 10; lymphoma n = 10; and solid tumors, n = 11) were treated weekly for 3 weeks with a 2-week rest; treatment consisted of a fixed dose of MTX (30 mg/m2 over 24 hours) followed by a 2-hour infusion of 6-TG in escalating doses. RESULTS Measurement of plasma MTX, 6-TG, and mononuclear 5-phosphoribosyl-1-pyrophosphate (PRPP) levels indicates that the desired biochemical modulation and serum levels were achieved. Nonhematologic toxicities were mild and the dose-limiting toxicity was bone marrow depression. A 300-mg/m2 dose of 6-TG with MTX is considered the MTD. Responses were noted in patients with lymphoma. CONCLUSION Encouraging antitumor effects were produced with this regimen in heavily pretreated patients with lymphoma, particularly Hodgkin's disease (HD). The durations of responses were 17, 13+, 12, 9, and 7+ months. A phase II trial of the MTX/6-TG combination is warranted for the treatment of relapsed lymphoma.
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Manonmani V, Tan CT. Malaysian children with: "benign epilepsy of childhood with centrotemporal spikes". Singapore Med J 1994; 35:247-9. [PMID: 7997896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Benign epilepsy of childhood with centrotemporal spikes (BECT) was studied in Malaysian children, and was observed in Chinese, Malay and Indian children in the ratio 10:6:5. There were 12 boys and 9 girls. Fit frequency varied from almost daily to a single fit. The age of onset ranged from 2-13 years and BECT was not noted in any child over 13 years old. There was a strong circadian rhythm and fits occurred mainly in sleep. Generalised seizures were more common than partial seizures. During the 3-year study from April 1989 to April 1992, 21 children with BECT were identified from the EEG records done at the University Hospital and it was found that this genetic epilepsy which is autosomal dominant with age dependent penetrance occurs in approximately 4.8% of our epileptic children. In addition there were 3 children in whom petit mal co-existed with a BECT EEG trait.
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Hsiao TY, Fu TC, Tan CT, Lee SY. An in vivo canine model for the study of phonation physiology by midbrain stimulation. J Formos Med Assoc 1994; 93:475-80. [PMID: 7858435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A versatile in vivo canine model is indispensable in studying the phonation function of the larynx. In this study, we attempted to build an in vivo phonation model in anesthetized dogs using stereotaxic electrical stimulation at a specific area in the midbrain. In each of the eight animals in this experiment, evoked phonation was successfully elicited by stimulating sites in the area ranging from 9 to 11 mm anterior, 3 to 5 mm lateral and 5 to 16 mm dorsal to the ear bar zero. This area was at the lateral border of the periaqueductal gray in the midbrain. The evoked-phonation process involved electrical stimulation of sites in this area, resulting in consistent responses by respiratory and laryngeal musculature accompanied by phonation. The evoked phonation could be consistently repeated. Different pitches of phonation were elicited by slightly moving the stimulation spots in this area. During evoked phonation, the subglottic aerodynamic power and individual laryngeal muscle action could be modified to study the effects of a single factor on the phonation process. The neuromuscular action for the control of phonation and the mechanical properties of the vocal folds can be investigated using an in vivo canine model.
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Mohamed R, Tan CT, Wong NW. Wilson's disease--a review of cases at University Hospital, Kuala Lumpur. THE MEDICAL JOURNAL OF MALAYSIA 1994; 49:49-52. [PMID: 8057991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The clinical course of 18 patients with Wilson's disease is reported. There were 13 males and five females of whom one is Malay. The prevalence of Wilson's disease in Malaysia is probably the same as elsewhere. Being a genetic syndrome, the genetic carrier rate for Wilson's disease is probably lower amongst the Malays. At diagnosis, the clinical signs were predominantly hepatic in 10 patients, neurological in five patients with three asymptomatic cases. All patients were commenced on penicillamine but poor compliance was observed in many patients. Two patients defaulted follow-up and seven patients died. Out of the nine surviving patients, only four are well with no clinical symptoms.
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Tan CT. The hot bath test among Malaysian multiple sclerosis patients. THE MEDICAL JOURNAL OF MALAYSIA 1994; 49:68-73. [PMID: 8057994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This is a study of 13 Malaysian patients with clinically definite Multiple sclerosis (MS) subjected to a hot bath test with VEPs, BAEPs, median nerve SSEPs before and after heating. Five patients (38%) developed neurological changes with the rise in body temperature. There was an average of 0.46 new sign per patient. Four patients had motor disturbances attributed mainly to aggravation of spinal cord dysfunction. Two patients had additional visual deterioration, one patient has associated VEP change. This study shows that though Uhthoff's phenomenon has not been noted in the reports of Asian MS patients, when subjected to rigorous testing, Asian MS patients also show sensitivity to body temperature change. However, the percentage of positivity of the hot bath test is much lower than that reported for Caucasians. Thus this study shows further differences between Asian and Caucasian MS patients.
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Sim EK, Wong ML, Tan CT, Lee CN. Histoacryl tissue adhesive: an alternative means of stopping polytetrafluoroethylene graft sweating. J Thorac Cardiovasc Surg 1993; 106:1227-8. [PMID: 8246570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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87
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Manonmani V, Tan CT. Juvenile myoclonic epilepsy--a report of 11 patients at the University Hospital, Kuala Lumpur. Singapore Med J 1993; 34:378-80. [PMID: 8153678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This is a report on 11 cases of Juvenile Myoclonic Epilepsy (JME) from the University Hospital, Kuala Lumpur, all of whom were diagnosed in the last one and a half years. This genetic syndrome is seen in all the three main racial groups: Chinese, Malays and Indians. It accounts for 2% of the epilepsy patients seen at the neurology clinic. Lack of awareness is the main hindrance to diagnosis.
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Lee MK, Cheng HM, Ng SC, Menaka N, Tan CT, Wang F. Antiphospholipid antibodies and stroke in the young--a study of three cases. THE MEDICAL JOURNAL OF MALAYSIA 1993; 48:330-5. [PMID: 8183147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cerebral infarction in the young is likely to be non-atheromatous. While in previous studies no cause has been found in 40% to 50% of patients, an increasing role for haemorheological factors is becoming apparent. Among these, an association between antiphospholipid antibodies (aPLs) and ischaemic cerebrovascular disease is now well-recognised. This entity has not been previously reported in Malaysian patients. In a study of 80 patients with stroke below the age of 50 years who were seen at the University Hospital, Kuala Lumpur, between January 1982 and May 1992, 3 patients with ischaemic cerebral infarction were found to have aPLs. aPLs was detected using ELISA method for anticardiolipin antibodies (aCLs), and presence of lupus anticoagulant (LA) was established by kaolin clotting time, thromboplastin inhibition test and platelet neutralisation procedure. Only 1 patient had active systemic lupus erythematous. Cerebrovascular events were recurrent in one of the 2 non-lupus patients. aPL-related stroke should be considered in young patients who have cerebral ischaemia occurring without obvious cause. More cases are likely to emerge in Malaysia with active screening.
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Tan CT. The hypochondriacal patient. Singapore Med J 1993; 34:78-80. [PMID: 8266137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Until recently, hypochondriasis received relatively little attention from clinical investigators. The epidemiology is largely unknown. The numerous theories on the aetiology cannot explain the psychopathology. Recent interest and attempts at operationally defining the syndrome have resulted in some progress in the recognition and treatment of the hypochondriacal patient. The physician's reaction is highlighted as an important factor that contributes to the initiation and maintenance of this difficult condition.
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Chui PP, Tan CT. Sudden death due to incarcerated Bochdalek hernia in an adult. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1993; 22:57-60. [PMID: 8503640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Bochdalek hernias presenting in adulthood are rare occurrences. They present commonly as acute surgical emergencies. A case of sudden death due to perforation of gastric ulcer in an incarcerated Bochdalek hernia is reported. This has not been previously documented. Recent literature on the subject is also reviewed.
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91
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Tan CT, Leong S. Evoked response study among Malaysian multiple sclerosis patients. Singapore Med J 1992; 33:575-80. [PMID: 1488664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A study of visual evoked potential (VEP), brainstem evoked potential (BAEP) and median nerve somatosensory evoked potential (SSEP) in 26 Malaysian patients with clinically definite Multiple Sclerosis (MS). This study showed an overall high rate of abnormality, with 85% of patients for VEP, 31% for BAEP and 65% for median nerve SSEP. The rate of abnormality was particularly high for patients who were symptomatic, reaching 100% of patients for VEP, 50% of patients in BAEP, 83% of nerves for median nerve SSEP. The rate of abnormality among those who were asymptomatic was lower, varying from 32% of eyes in VEP, 27% of patients in BAEP and 31% of nerves in median nerve SSEP. Three out of 10 patients with optic spinal form of MS have abnormal BAEP. These show the usefulness of the evoked potential studies in confirming the clinical lesions as well as demonstrating subclinical involvement. The rate of abnormal evoked responses for the asymptomatic patients in this study is generally lower than that published elsewhere.
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Chow TC, Tan CT, Hwang YS, Ting MC, Chen YP, Lin JC, Lin CC. Sudden cardiac arrest during left thoracoscopic T2 sympathectomy. MA ZUI XUE ZA ZHI = ANAESTHESIOLOGICA SINICA 1992; 30:277-82. [PMID: 1344244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
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Lee BP, Tan CT. Comminuted intra-articular fracture of the distal radius--results of early open reduction and internal fixation. Singapore Med J 1992; 33:612-5. [PMID: 1488673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Comminuted intra-articular fracture of the distal radius remains a challenging problem. This article reviews the results of 15 consecutive cases which were treated with open reduction and internal fixation with T-plate after failing to achieve articular congruency with closed reduction. The follow-up ranges from 20 months to 28 months. In thirteen cases, articular congruency was restored. However, 4 of these 13 cases later lost some of the articular congruency. This suggests the need for supplementary bone grafting. Reduction of the extra-articular portion of distal radius was generally well maintained. There was an average of 2.4 mm loss in styloid height, an increase of 1.2 mm in ulnar variance and loss of 12.5 degrees of volar tilt. Seven patients (46%) were completely pain-free, with the remaining 8 patients (53%) experiencing mild pain associated with forceful activities involving the wrist. All patients achieved a functional range of motion. Grip strength averaged 81% of the uninjured side. Of the 12 patients who were engaged in active employment, 10 returned to their previous job within 4 months of injury (average 8.5 weeks). The only complication in this series was the development of reflex sympathetic dystrophy in a 68-year-old housewife. We recommend open reduction and internal fixation if closed reduction fails to achieve articular congruency in comminuted distal radius fractures.
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Sim EK, Lee CN, Mestres CA, Lim LC, Adebo OA, Tan CT. Coronary artery bypass surgery in young patients. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1992; 62:618-21. [PMID: 1642582 DOI: 10.1111/j.1445-2197.1992.tb07532.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Coronary atherosclerosis is being increasingly observed in young patients. However results of surgery in such patients have so far been disappointing both in terms of operative mortality, symptomatic relief and long-term survival. Reasons given for this include the increased prevalence of risk factors in young patients and a higher incidence of graft occlusion. In the treatment of Asian patients, a further negative factor is the belief that coronary artery disease is more often diffuse and the vessels smaller. Between January 1987 and May 1991, a total of 66 patients under the age of 45 years at the time of surgery had coronary artery bypass grafting performed. The demographic, clinical, angiographic and operative data were analysed. Eighty-nine per cent of the patients were male and their racial distribution was 63% Chinese, 8% Malays, 26% Indians and 3% Others. Their mean age was 40.8 years. The presence of risk factors was high: 45.6% had hypertension; 34.8% were smokers; 21.2% had diabetes mellitus; and 12.1% had hyperlipidaemia. The main indication in these patients was either angina or a previous myocardial infarction (53%). There were no patients with perioperative infarction diagnosed by the presence of new Q wave. There was no hospital death. The stay of the patients ranged from 6 to 28 days with a mean of 10 days. Follow-up ranged from 3 to 54 months. There were no late deaths. It was concluded that there is a high incidence of risk factors among young patients with coronary artery disease, which follows the pattern of many other studies. The operative risk in these patients is low and morbidity is minimal.(ABSTRACT TRUNCATED AT 250 WORDS)
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Liang TS, Tan CT, Tay BK, Krishnamoorthy S. Giant cell tumours of the sacrum. Singapore Med J 1992; 33:255-9. [PMID: 1631583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Giant Cell Tumours (GCT) of the Bone is one of the commoner primary bone tumours. Although considered a benign tumour, it does occasionally metastasize to the lungs. Treatment modalities vary according to the surgical staging and the site of the tumour. Treatment is further complicated when the tumour occurs in difficult locations like the sacrum. The paper includes a review of literature into treatment options and the presentation of 3 patients with sacral GCTs, one of which also has multiple pulmonary metastases from a "benign" giant cell tumour.
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Chye ML, Tan CT, Chua NH. Three genes encode 3-hydroxy-3-methylglutaryl-coenzyme A reductase in Hevea brasiliensis: hmg1 and hmg3 are differentially expressed. PLANT MOLECULAR BIOLOGY 1992; 19:473-84. [PMID: 1377968 DOI: 10.1007/bf00023395] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) catalyses an important step in isoprenoid biosynthesis in plants. In Hevea brasiliensis, HMGR is encoded by a small gene family comprised of three members, hmg1, hmg2 and hmg3. We have previously described hmg1 and hmg2 (Plant Mol Biol 16: 567-577, 1991). Here we report the isolation and characterization of hmg3 genomic and cDNA clones. In comparison to hmg1 which is more highly expressed in laticifers than in leaves, the level of hmg3 mRNA level is equally abundant in laticifers and leaves. In situ hybridization experiments showed that the expression of hmg3 is not cell-type specific while hmg1 is expressed predominantly in the laticifers. Primer-extension experiments using laticifer RNA showed that hmg1 is induced by ethylene while hmg3 expression remains constitutive. The hmg3 promoter, like the promoters of most housekeeping genes, lacks a TATA box. Our results suggest that hmg1 is likely to encode the enzyme involved in rubber biosynthesis while hmg3 is possibly involved in isoprenoid biosynthesis of a housekeeping nature.
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Tan CT, Schaff HV, Miller FA, Edwards WD, Karnes PS. Valvular heart disease in four patients with Maroteaux-Lamy syndrome. Circulation 1992; 85:188-95. [PMID: 1728449 DOI: 10.1161/01.cir.85.1.188] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Maroteaux-Lamy syndrome is a lysosomal storage disease of mucopolysaccharide metabolism (MPS type VI) that may involve the mitral and aortic valves. Affected patients have other skeletal and oropharyngeal malformations that complicate anesthetic and surgical management. METHODS AND RESULTS The present report describes the clinical, echocardiographic, and pathological findings in four patients with Maroteaux-Lamy syndrome. Two of three siblings underwent successful double-valve replacement for aortic and mitral valve stenoses. The third sibling, whose aortic and mitral valves were thick and fibrotic, died from septicemia after hip surgery. A fourth, unrelated patient also had successful double-valve replacement. CONCLUSIONS Our experience emphasizes the potential difficulties in preoperative assessment and surgical treatment as well as the unique problems related to airway management in patients with this syndrome.
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Abstract
OBJECTIVE --To assess the cardiac status of long-term survivors of pediatric malignancies who received chemotherapy, including anthracyclines. DESIGN AND METHOD -Patients were evaluated by echocardiogram from 4 to 20 years (median, 7 years) after completion of anthracyclines, with prospective and retrospective analysis. PATIENTS --The consecutive sample of 201 patients had received a total anthracycline dose of 200 to 1275 mg/m2 (median, 450 mg/m2), and 51 patients had mediastinal radiotherapy. MAIN OUTCOME MEASURES --The overall incidence and severity of abnormal systolic cardiac function were determined for the entire cohort. Risk factors of total anthracycline dose, mediastinal radiotherapy, age during treatment, and length of follow-up were examined. RESULTS --Twenty-three percent (47/201) of the cohort had abnormal cardiac function on noninvasive testing at long-term follow-up. Correlation between total cumulative dose, length of follow-up, and mediastinal irradiation with incidence of abnormalities was significant. Fifty-six patients were followed up for 10 years or more (median, 12 years), with a median anthracycline dose of 495 mg/m2. Thirty-eight percent (21/56) of these patients, compared with 18% (26/145) of patients evaluated after less than 10 years, had abnormal findings. Sixty-three percent of patients followed up for 10 years or more after receiving 500 mg/m2 or more of anthracyclines had abnormal findings. Nine of 201 patients had late symptoms, including cardiac failure and dysrhythmia, and three patients died suddenly. Microscopic examination of the myocardium on biopsy and autopsy revealed fibrosis. CONCLUSION --The 23% incidence of late cardiac abnormalities warrants continued evaluation of patients after anthracyclines to guide patient care and the design of future chemotherapeutic protocols.
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Chye ML, Kush A, Tan CT, Chua NH. Characterization of cDNA and genomic clones encoding 3-hydroxy-3-methylglutaryl-coenzyme A reductase from Hevea brasiliensis. PLANT MOLECULAR BIOLOGY 1991; 16:567-77. [PMID: 1714317 DOI: 10.1007/bf00023422] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Hevea brasiliensis is the major producer of natural rubber which is cis-1,4-polyisoprene. The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) is involved in the biosynthesis of rubber and other plant products. We have used a hamster HMGR cDNA clone as a heterologous hybridization probe to isolate and characterize cDNA and genomic clones of HMGR from H. brasiliensis. Sequence analysis revealed that these clones fall into two different classes, HMGR1 and HMGR2. Comparison of the two classes shows 86% nucleotide sequence homology and 95% amino acid homology. The carboxy-termini of Hevea HMGRs are highly homologous to those of hamster, yeast and Arabidopsis HMGR. The amino-terminus of Hevea HMGR contains two potential membrane-spanning domains as in Arabidopsis HMGR while seven such domains are found in the HMGRs of other organisms. The apparent molecular mass of Hevea HMGR was estimated in western blot analysis to be 59 kDa. Northern blot analysis indicated that the HMGR1 transcript of 2.4 kb is more highly-expressed in laticifer than in leaf. Genomic Southern analysis using 3'-end cDNA probes indicates the presence of at least two HMGR genes in Hevea.
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Tan CT, Abdullah D, Zakariya AH. CT scan changes in multiple sclerosis among Malaysian patients. Neuroradiology 1991; 33:494-8. [PMID: 1780049 DOI: 10.1007/bf00588039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A study of 12 patients with clinically definite multiple sclerosis (CDMS) using high dose infusion CT showed overall abnormality of 75% with an average of 2.5 lesions per patient. 75% of the patients showed abnormality of the cerebrum, mostly asymptomatic. The main changes were ventricular dilatation and asymmetry, isolated or generalized cerebral atrophy, areas of low attenuation mainly in the deeper parts of the cerebrum and the peri-ventricular area. 25% of the patients showed changes in the brainstem and none was seen in the cerebellum. The abnormality was more florid in patients with clinically disseminated forms of the disease. The study demonstrated that asymptomatic cerebral involvement is common among Asian patients with MS and CT is a useful tool in the overall assessment and diagnosis of Asian MS patients.
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