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Biomedical subjects

N Kunaratnam

Publications and source records attributed to N Kunaratnam.

13 recordsLinked to original sources
PubMed1991

Otorhinolaryngology--head and neck surgery--its beginnings and development in Singapore.

Otolaryngology which had a modest beginning in Singapore as part of general surgery in the late twenties, developed into a full-fledged independent unit by 1957. From the provision of simple basic emergency and secondary patient care during the early period, the speciality has progressed steadily to its present advanced state where its area has been enlarged from the traditional Ear, Nose and Throat to extend from the Skull Base down to the Neck. Microsurgery was introduced in 1958 and this enabled widening of the scope of work. Increased traineeship programmes along with subspecialisation in various fields in Otolaryngology have significantly enlarged the pool of available specialists. This, together with advanced diagnostic and supportive facilities have contributed to much better patient management.

History, 20th Century↗
PubMed1988

Middle ear diseases in cleft palate patients in Singapore.

A preliminary prospective study of the correlation between middle ear diseases and cleft palate was started in February 1987. Eighty three patients from the Plastic Surgical Department of the Singapore General Hospital have been screened. Three quarters of the ears screened were normal. Middle ear effusion was the commonest disease especially in younger children found in eighteen of thirty four abnormal ears; all these patients benefited from myringotomy and insertion of a ventilating tube. Other types of middle ear disease included adhesive otitis media, perforation of the eardrum, attic retraction and cholesteatoma; these were found predominantly in older patients. The incidence of middle ear disease was 23% in Chinese patients with cleft palate as compared with up to 90% in Caucasian patients.

Adolescent↗
PubMed1988

Surgery of major congenital aural atresia.

Accurate preoperative clinical, audiometric and radiographic evaluation is a prerequisite for surgery of major congenital aural atresia, which is accepted as one of the most difficult otological reconstructive procedures to perform. The main aim is to achieve serviceable hearing. Middle ear and facial nerve anomalies and functional results of eleven consecutive primary operations by one of the authors are presented. Familiarity with various Tympanoplastic and Facial nerve surgical techniques is mandatory.

Adolescent↗
PubMed1985

HLA and nasopharyngeal carcinoma in Malays.

HLA associations were observed in unrelated Malay patients with nasopharyngeal carcinoma (NPC). HLA-B18 was observed in 18/45 (40%) Malay NPC patients compared to 22/167 (13%) Malay normals (P = 0.0001; Pc = 0.0027, RR = 4.4). The frequency of HLA-B17, one of the antigens associated with Chinese NPC, was also increased among Malay NPC (13/45 29%) compared to controls (18/167 11%; P = 0.003, Pc = 0.07 RR = 3.4). Similar to the findings among Chinese NPC, the frequency of B17 was higher in early onset (less than or equal to 30 years) Malay NPC resulting in a higher relative risk (RR = 5.0).

Adult↗
PubMed1985

Auditory brainstem responses in normal hearing ears.

It is essential to know the expected auditory brainstem response latencies of a normal hearing population to utilise this procedure as a diagnostic tool. Absolute wave latencies of the auditory brainstem responses were recorded on 50 normal hearing subjects, aged 3 months to 56 years using a standard sound pressure level of 115 dB alternate clicks. The recordings were examined for differences in latencies between the age groups, sexes and the left and right ears. The results showed that the absolute latencies of subjects aged 2 years and above were the same and no significant differences were obtained between the left and right ears. The infants showed longer latencies. The brainstem transmission time values were calculated as from Wave NI-NIII, Wave NI-NV and Wave NIII-NV. A comparison of the brainstem transmission times between the left and right ears of each individual subject showed that in all cases the differences did not exceed more than 0.2 msec. A value of more than 0.2 msec between the two ears of an individual may be of diagnostic importance. In comparing the male and female brainstem transmission times, there was a significant difference statistically. Another value to use was the Wave PV, which is the most prominent and stable peak. The results showed that the Wave PV latency progressively shortens during infancy to attain the adult value somewhere between 18 and 24 months.

Acoustic Stimulation↗
PubMed1983

Epstein-Barr virus specific T-cell response in nasopharyngeal carcinoma patients.

There is a substantial body of evidence suggesting an association between Epstein-Barr virus (EBV) and undifferentiated nasopharyngeal carcinoma (NPC). The present study has compared a group of NPC patients (newly diagnosed and long-term survivors) and controls for EBV-specific T-cell immunity using the regression of transformation assay. Newly diagnosed patients (17 tested) when compared with either long-term survivors (20 tested) or controls (30 tested) showed a significant impairment in virus-specific T-cell immunity (p = 0.036, p = 0.043 respectively). Furthermore, donors with IgA antibody to EBV showed a significant depression in virus-specific T-cell immunity compared with donors without IgA antibody (19 IgA-positive, 48 IgA-negative; p = 0.0025). These results may be important in explaining the postulated role of EBV in the aetiology of NPC.

Antibodies, Neoplasm↗
PubMed1983

HLA and nasopharyngeal carcinoma in Chinese--a further study.

This paper reports the results of 8 years of HLA typing of newly diagnosed nasopharyngeal carcinoma (NPC) patients among Chinese in Singapore, and compares the HLA profile of NPC cases with that of the normal Chinese population. Earlier results had indicated an association with A2 and BW46, but the heterogeneity of the earlier case series, which contained a proportion of long-term survivors, obscured other aspects of the relationship. In this paper, the risk associated with A2 (relative risk = 1.5) and BW46 (relative risk = 1.9) is confirmed, showing a much higher relative risk in the presence of both antigens, and a risk is also demonstrated for B17 (relative risk = 2.1). Relative risks of less than unity are observed for AII (relative risk = 0.5) and B13 (relative risk = 0.5). Data from family studies indicate the importance of the haplotype A2.BW46 in determining risk for NPC.

Adult↗
PubMed1983

Teratoid carcinosarcoma of the paranasal sinuses.

Malignant tumours with teratoid or blastomatous features are exceptionally rare in the upper respiratory tract with only 8 documented cases, including the 3 in this report. The tumours occurred in adults aged 27 to 62 yr, and the sites of origin were the ethmoid sinus (4 cases), ethmoid and other paranasal sinuses (2 cases), unspecified sinuses (1 case) and nasopharynx (1 case). The disease was rapidly fatal in 3 cases in which treatment was restricted to surgery and was associated with longer survivals in those given supportive radiotherapy. The tumours are locally aggressive and may invade soft tissues, bone, orbit and cranial cavity. Histologically, the tumours are characterized by a mixture of epithelial and mesenchymal components including cellular elements with immature or embryonal characteristics. These tumours, variously termed malignant teratoma, blastoma, teratocarcinoma or teratoid carcinosarcoma, probably comprise a homogeneous group of neoplasms since their histological and biological features are essentially similar. It is postulated that the tumours develop from primitive embryonic tissues or pluripotential cells that have remained sequestered in the sinonasal tract.

Adult↗
PubMed1979

Effect of 17 phenyl PGF2 alpha on nasal patency in man.

The effect of three different doses (12.5 microgram, 25 microgram and 50 microgram) of 17 phenyl PGF2 alpha on nasal patency in fourteen patients with vasomotor rhinitis was studied on separate occasions. In all subjects the three doses of the prostaglandin analogue increased nasal patency for varying duration. With the 50 microgram single dose the duration of action ranged between three hours and more than seven hours. There were no side effects in most of the patients.

Dinoprost↗
PubMed1978

Effect of topical prostaglandins on nasal patency in man.

The effect of prostaglandin E1 and 17 phenyl trinor PGE2 on nasal patency has been studied in healthy volunteers and in patients with vasomotor and allergic rhinitis. Both drugs applied topically increased nasal patency. The effect of a single dose of either compound lasted for several hours. Prostaglandin E1 produced nasal irritation and throbbing, lacrimation, headache and sore throat. Except for occasional brief nasal irritation, these side effects were not encountered with 17 phenyl trinor PGE2.

Clinical Trials as Topic↗