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Biomedical subjects

K K Tan

Publications and source records attributed to K K Tan.

At least 19 recordsLinked to original sources
PubMed1992

Blood cyclosporin concentrations but not doses correlate with acute changes in renal function following heart and heart-lung transplantation.

The relationship between changes in cyclosporin (CyA) dose or CyA blood concentration and the reciprocal creatinine concentration was investigated by cross-correlation analysis over the first 3 postoperative months in 32 consecutive heart and heart-lung recipients. Exploratory analysis suggested that early changes in renal function, probably attributable to recovery from preoperative cardiac failure, obscured later underlying correlations. Therefore, all data up to the first nadir in plasma creatinine following transplantation were excluded from the analysis. Five-day mean CyA doses or blood concentrations were cross-correlated with 5-day mean reciprocal creatinine concentrations measured either in the same 5-day period or with the creatinine measured up to two 5-day periods later. Although a significant correlation was found between CyA dose and blood concentration (the 95% confidence interval of the population correlation coefficient did not overlap zero), there was no relationship between dose and changes in renal function. The blood CyA concentration, however, correlated significantly with the reciprocal creatinine concentration measured in the same 5-day period and was also predictive of changes in creatinine measured in the subsequent 5-day period. Thus, a major criterion for therapeutic drug monitoring had been fulfilled: CyA dosage adjustment based on blood CyA concentrations, as the intermediate therapeutic end point, is helpful in the management of acute nephrotoxicity in heart and heart-lung transplant recipients because of the lack of a dose-effect relationship. Regular CyA monitoring and appropriate dosage adjustment is essential for the management of acute nephrotoxicity in the first 3 months following heart or heart-lung transplantation.

Creatinine↗
PubMed1992

Blood cyclosporin concentrations and the short-term risk of lung rejection following heart-lung transplantation.

1. The relationship between blood cyclosporin concentration (CyACb) and a patient's risk of organ rejection following heart-lung (HL) transplantation was investigated. 2. Longitudinal data were collected for 90 days post-operation for 31 HL transplant recipients. Following exploratory analysis, a multiple logistic regression model with a binary outcome variable representing presence or absence of lung rejection (as defined on biopsy findings and/or intention to treat) in the next 5 days was fitted to the data. 3. A significant interaction between time post-transplant and CyACb was found. During weeks 1-3, the relative risk (RR) of rejection per unit increase in log(e) (5-day mean CyACb) was reduced: RR = 0.29, 95% confidence interval (CI) = (0.12, 0.72). After 3 post-operative weeks, this trend was reversed: RR = 1.61, 95% CI = (0.96, 2.70). Increases in cyclosporin dose (CyAD) and in coefficient of variation (CV) for both CyAD and CyACb over the previous 10 days significantly increased the risk of rejection: RR per unit increase in log(e) (5-day mean CyAD) = 2.72, 95% CI = (1.18, 6.25); RR per increase of 10% (i.e. from, say, 20% to 30%) in the CV for CyAD = 1.20, 95% CI = (1.07, 1.36); RR if the CV for CyACb > 40% = 1.51, 95% CI = (1.01, 2.27). Administration of high dose steroids in the previous 5 days was found to protect against further rejection: RR if steroid treatment was given = 0.23, 95% CI = (0.13, 0.38).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mumps encephalomyelitis.

A 7-year-old Indian girl developed complete paralysis of her lower limbs and acute urinary retention 10 days after suffering from mumps. Encephalomyelitis due to mumps was not suspected initially since it is a rare complication of mumps, although relatively well-documented. However, the preceding history of parotitis and the presence of mumps-specific IgM in both blood and cerebrospinal fluid led to the diagnosis. The initially severe acute neurological deficits resolved completely three months after onset of her illness. Serological investigations were helpful in diagnosing neurological complications of mumps in this case, and especially where there is no preceding parotitis.

Child↗
PubMed1991

Auditory canal haemorrhage following mandibular condylar fracture.

A case of haemorrhage from the external auditory meatus associated with condylar fracture is presented. It is important that haemorrhage from the ear following maxillofacial injuries be investigated thoroughly because displacement of the condyle into the middle cranial fossa also presents in this manner. The patient was treated by intermaxillary fixation and packing of the auditory canal. Packing is not only effective for haemostasis but is also important in preventing subsequent stenosis of the auditory canal.

Adult↗
PubMed1991

Does training reduce the incidence of industrial hand injuries?

The incidence of industrial hand injuries remains high despite the introduction of statutory measures and other advances in health and safety awareness. A prospective study was undertaken to determine if training before employment helps to reduce these injuries. A significant number of patients did not receive any training and this may have played a part in their injury but other contributory factors, such as human error, must also be taken into consideration. Some recommendations are made for future prevention.

Accidents, Occupational↗
PubMed1991

CT-directed BRW stereotactic neurosurgery: local experience with 42 cases.

Initial experience with the Brown-Roberts-Wells (BRW) computed tomographic (CT)-guided stereotactic system is reported. Forty-two procedures were performed over a 22-month period on 21 female and 20 male patients (one patient had a repeat procedure). Their ages ranged from 11 years to 89 years. These included 21 stereotactic biopsy procedures, 2 stereotactic implantations of third ventricular catheters through the foramen of Monro for intraventricular opiate insertion in terminal cancer patients, 2 stereotactic aspirations for brain abscess, 10 stereotactic aspirations of intracerebral haematomas, 3 stereotactic aspirations of cystic brain tumours, 1 stereotactic placement of a fourth ventricle-peritoneal shunt and lastly 3 stereotactic craniotomies. Successful targeting was achieved in all cases. There was one operation-related complication which resulted in uncontrollable intracerebral haemorrhage and ultimately led to the patient's demise.

Adolescent↗
PubMed1991

Tuberculosis in the elderly.

A study of 120 cases of tuberculosis in patients aged 65 years and above revealed that there were more males than females with the disease compared with the younger age group of 15 to 45 years old. The elderly group also had significantly more severe and more had bacteriologically positive disease. The majority of them were born outside Singapore and immigrated more than 30 years ago. Risk factors such as diabetes mellitus, past history of tuberculosis, malignancy and gastrectomy were more common in the elderly group. Standard 6-month regimens were well tolerated and adverse side effects to the drugs were negligible.

Adolescent↗
PubMed1991

Actinomycosis of the brain.

Actinomyces species are rare but treatable causes of central nervous system infection. A case of actinomycotic cerebral abscess is reported. The primary source of infection was probably the lung based on radiological findings although culture of the bronchial brushings was negative. The patient had surgical excision and repeated drainage with two prolonged causes of antibiotic therapy. At follow-up examination 36 months later, the patient was well except for a residual left hemiplegia. Diagnosis of cerebral actinomycosis can be made by anaerobic culture of the appropriate specimens or on histologic grounds. Optimal management combines adequate surgical drainage and prolonged antibiotic therapy.

Actinomycosis↗
PubMed1991

Sympathectomy for wet, dripping palms.

An analysis of upper thoracic sympathectomy for palmar hyperhydrosis performed in a Neurological Department for the past ten years via several surgical approaches suggests that the posterior median approach is preferable. Histological confirmation of ganglion cells at time of surgery is recommended.

Adolescent↗
PubMed1990

A simple penile dressing following hypospadias surgery.

A single layer of surgical gauze applied with adhesive provides a simple and inexpensive dressing for use following hypospadias repair. It splints the penis to the abdomen, supports the wound and secures the catheter while permitting observation and wound care.

Bandages↗
PubMed1990

Snake bite in Kelantanese children: a five year experience.

The records associated with 83 children from 16 months to 12 years of age who were admitted with snake bite to Kota Bharu General Hospital and University Hospital, Universiti Sains Malaysia over a 5 year period were reviewed. Elapid bites were more common than viper bites while sea-snake bites were not recorded. Symptoms were relatively mild, the common clinical features being pain and local swelling. Antivenom therapy was required in 11 children. Only three of the 11 children developed minor adverse reactions to antivenom. Four of the 83 required ventilatory support for respiratory failure and two children died.

Antivenins↗
PubMed1990

Altered pharmacokinetics of cyclosporin in heart-lung transplant recipients with cystic fibrosis.

The cyclosporin dose versus blood concentration relationship for 11 heart-lung transplant recipients with cystic fibrosis was studied retrospectively. Eleven patients, closely matched for age and gender, who received heart-lung transplantation for other diseases were selected as controls. Cystic fibrosis patients received 16.7 (SD 7.2) mg/kg/day of oral cyclosporin compared with 8.2 (SD 1.9) mg/kg/day given to the control patients (p less than 0.01). Nine of the cystic fibrosis patients received higher mean daily doses of cyclosporin. Mean blood cyclosporin concentrations were, however, not significantly different (p = 0.58), and there were no apparent differences in clinical outcome in terms of rejection, infection, and nephrotoxicity in the two groups. The apparent oral clearance of cyclosporin was significantly higher (p less than 0.01) in cystic fibrosis patients. Cyclosporin dosage individualization with the aid of cyclosporin blood concentration measurements is critically important in this subpopulation of heart-lung transplant recipients.

Administration, Oral↗
PubMed1990

Effect of ciprofloxacin on the pharmacokinetics of antipyrine in healthy volunteers.

The pharmacokinetics of antipyrine was studied in six healthy male volunteers before and during a 6-day course of 750 mg oral ciprofloxacin b.d. Antipyrine clearance was significantly decreased and the half-life significantly prolonged (P less than 0.05) during ciprofloxacin treatment. No significant difference in the apparent volume of distribution of antipyrine was observed. The results of this study suggest that ciprofloxacin is a potent inhibitor of hepatic drug metabolism.

Adult↗
PubMed1990

Three-dimensional magnetic resonance images of the brain: application to neurosurgical planning.

Data from single 10-minute magnetic resonance scans were used to create three-dimensional (3-D) views of the surfaces of the brain and skin of 12 patients. In each case, these views were used to make a preoperative assessment of the relationship of lesions to brain surface structures associated with movement, sensation, hearing, and speech. Interactive software was written so that the user could "slice" through the 3-D computer model and inspect cross-sectional images at any level. A surgery simulation program was written so that surgeons were able to "rehearse" craniotomies on 3-D computer models before performing the actual operations. In each case, the qualitative accuracy of the 3-D views was confirmed by intraoperative inspection of the brain surface and by intraoperative electrophysiological mapping, when available.

Adolescent↗
PubMed1990

An evaluation of 1987 tuberculosis deaths in Singapore.

Tuberculosis was responsible for 177 deaths in 1987. This study evaluated the accuracy of tuberculosis death certification by hospital doctors and general practitioners in 111 cases where hospital case-notes were available for verification. It revealed that only 49 cases (44%) died of active tuberculosis, 12 (11%) died of late effects of tuberculosis and 41 (37%) died of causes unrelated to tuberculosis. There was no evidence of tuberculosis in 9 cases. Only 39 cases (56%) of active tuberculosis certified by hospital doctors were correct compared to 10 (24%) certified by general practitioners. Hospital doctors certified 6 out of 9 deaths which had no evidence of tuberculosis. The actual tuberculosis mortality rate was estimated to be between 1.9 and 4.9 per 100,000 instead of the officially published 6.8 per 100,000 for 1987.

Adolescent↗
PubMed1989

Co-administration of ciprofloxacin and cyclosporin: lack of evidence for a pharmacokinetic interaction.

Ciprofloxacin is widely reported to lower theophylline clearance in patients. Since cyclosporin and theophylline are metabolized by cytochrome P-450 enzymes in the human liver, we investigated whether ciprofloxacin could alter the pharmacokinetics of cyclosporin in healthy volunteers. There was no significant difference (P greater than 0.05) in the pharmacokinetic parameters estimated for cyclosporin without and during ciprofloxacin administration. The results of the present study suggest that ciprofloxacin is unlikely to affect the pharmacokinetics of cyclosporin to a clinically important extent at a dosage of 500 mg twice a day.

Adult↗