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Biomedical subjects

W T Tan

Publications and source records attributed to W T Tan.

At least 37 records · Page 2Linked to original sources
PubMed1994

The genetic basis of malignant hyperthermia.

Malignant hyperthermia (MH) susceptibility remains the commonest cause of death owing to general anaesthesia. In humans, genetically predisposed to MH, anaesthesia can induce skeletal muscle rigidity, hypermetabolism and hyperthermia, which if not immediately reversed can lead to tissue injury and death. In swine, the corresponding condition leads to stress-induced deaths and devalued meat products. Aberrant behaviour in the calcium (Ca2+) release channel (the ryanodine receptor) of skeletal muscle sarcoplasmic reticulum has been implicated in the cause of both the porcine and human syndromes by biochemical, physiological and molecular genetic analysis. In swine, a single mutation in the ryanodine receptor gene (RYR1) can account for all cases of MH in all breeds, but a series of different RYR1 mutation are uncovered in human families with MH. In addition, the lack of linkage between MH and RYR1 in some families indicates a heterogeneous genetic basis for the human MH.

Animals↗
PubMed1993

The solitary thyroid nodule revisited.

A series of 195 clinically solitary thyroid nodules is presented and compared with a matching series reported a decade ago. Changes in the pattern of presentation, preoperative diagnosis and options of operative management are highlighted. Although the pattern of presentation has not changed significantly over the last decade, there was a shift noted towards reliance on fine needle aspiration for preoperative diagnosis. The false negative rate was two percent in this series and there were no false positives. There was also a shift towards more conservative surgery in the form of "nodulectomies" in the present series compared to the previous one. The incidence of malignancy in this series was 10.2 percent.

Adolescent↗
PubMed1993

Changing patterns in the treatment of early breast cancer: a historical perspective and a review of changing local trends.

Over the past 50 years, a variety of surgical procedures have been advocated for the treatment of operable breast cancer, ranging from local excision to supraradical mastectomy. Today, the surgical treatment of breast cancer remains highly contentious. We review the historical development of breast cancer surgery and analyse the available evidence supporting conservative procedures. We also express our opinions on the treatment of early breast cancer and illustrate the changing patterns of surgery with our experience at National University Hospital.

Breast Neoplasms↗
PubMed1992

Transareolar dye-injection microdochectomy.

Single-duct microdochectomy is described for use in patients with bloody or serosanguinous nipple discharge arising from a single duct in the breast. Because most such cases are caused by benign, intraductal papillomata, the technique used in removing the offending ductal system should be fully diagnostic, adequately therapeutic, and cosmetically acceptable. A technique is described that is used in 40 consecutive patients with good diagnostic, therapeutic, and cosmetic result. The procedure itself combines techniques and principles of plastic and reconstructive surgery such as minimal tissue trauma, use of anatomical tissue planes, bloodless-field surgery, and microdissection.

Breast↗
PubMed1988

Solubilities of trace copper and lead species and the complexing capacity of river water in the Linggi River Basin.

Chemical forms of copper and lead in river water of the Linggi River Basin have been fractionated into ASV labile, moderately labile, slowly labile, and inert metal species, based on a previously proposed scheme. Free (hydrated) metal ions were identified by a potentiometric method using an ion selective electrode. Speciation results showed that the soluble copper and lead species occurred mainly in the moderately labile and slowly labile fractions. The speciation results are primarily interpreted in terms of organic interaction due to agricultural based and light industries, and urban discharges. The measured metal complexing capacity (MCC) of the samples reveals consistency of the results with the nature of the discharge. MCC correlates reasonably well with the value from the permanganate test on the river water. In general, the speciation pattern was found to be consistent with the findings of other workers.

Journal Article↗
PubMed1987

Some aspects of breast cancer in Singapore--a review of 306 cases.

A retrospective study of 306 cases of carcinoma breast in Singaporean patients managed at the University Department of Surgery, Singapore General Hospital was made, based on all available case notes, pathology report forms, operation record books, Cancer Registry Notification Forms, and data obtained from the Registry of Births and Deaths. These cases had their initial histological diagnosis made between 1970 to 1978. Basic data like age distribution, sex distribution and racial distribution of our cases are presented. Aspects of breast cancer like stage at time of diagnosis and 5- and 10-year survival figures are also presented. The crude five-year survival for all 306 cases was 56% and the crude 10-year survival for 223 cases was 22%. Survival for small lesions (T1, or less than 2 cm) was 90% at five years and 68% at ten years, a rate comparable with most centres in the world.

Adult↗
PubMed1987

The rat groin flap as an experimental model in microsurgery.

The value of the rat groin flap in microsurgical experiments is discussed. It provides the practising microsurgeon, whatever his specialty, the opportunity to work on vessels ranging from 0.4 mm to 2.0 mm in diameter as well as on small nerves. The single, long, microvascular pedicle of this flap enables numerous experimental procedures to be performed. Most important of all, long term patency of the vessels after anastomosis can be assessed by observing changes in the flap. Rat groin flaps have been used in microsurgery for evaluating techniques of end-to-end and end-to-side anastomoses, testing microvascular auto-and allografts, studying the delay phenomenon in flap surgery, evaluating and comparing the effects of various vasodilator drugs on microvessels and for assessing the effects of avulsion and tension forces on blood vessels and nerves. These aspects are described and discussed.

Animals↗
PubMed1986

Mandibular ameloblastoma in Singapore--a 10 year review.

This paper reviews 30 cases of mandibular ameloblastoma seen and managed in the Singapore General Hospital over a 10 year period from 1976 to 1985 inclusive. Data on age and sex distribution, mode of presentation, presenting symptoms, size of tumour at time of presentation, radiological features at time of diagnosis, method of treatment and post-operative complications are discussed. There was no case of local recurrence in the 28 cases that were surgically managed. The importance of adequate local excision is emphasised. This paper also compares our local data with that of equivalent studies made in Thailand (Far East), Sweden (Europe) and Nigeria (Africa). An interesting rare case of malignant mandibular ameloblastoma is included in this study.

Adolescent↗
PubMed1981

The "wrap-around" end-to-side anastomosis for micro-vessels.

A new technique of end-to-side microvascular anastomosis is described. Using the rat groin flap model this technique was used to anastomose the superficial epigastric artery to the femoral artery. It proved successful with a 100% patency rate in 15 successive animals. Three flaps developed complications unrelated to the anastomosis which necessitated termination of the experiment after 3 days, but the remaining 12 anastomoses were functioning well when examined after 4 weeks.

Animals↗