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Biomedical subjects

L H Lim

Publications and source records attributed to L H Lim.

29 records · Page 2Linked to original sources
PubMed1997

Inhibition of poly (ADP-ribose) synthetase attenuates neutrophil recruitment and exerts antiinflammatory effects.

A cytotoxic cycle triggered by DNA single-strand breakage and poly (ADP-ribose) synthetase activation has been shown to contribute to the cellular injury during various forms of oxidant stress in vitro. The aim of this study was to investigate the role of poly (ADP-ribose) synthetase (PARS) in the process of neutrophil recruitment and in development of local and systemic inflammation. In pharmacological studies, PARS was inhibited by 3-aminobenzamide (10-20 mg/kg) in rats and mice. In other sets of studies, inflammatory responses in PARS-/- mice were compared with the responses in corresponding wild-type controls. Inhibition of PARS reduced neutrophil recruitment and reduced the extent of edema in zymosan- and carrageenan-triggered models of local inflammation. Moreover, inhibition of PARS prevented neutrophil recruitment, and reduced organ injury in rodent models of inflammation and multiple organ failure elicited by intraperitoneal injection of zymosan. Inhibition of PARS also reduced the extent of neutrophil emigration across murine mesenteric postcapillary venules. This reduction was due to an increased rate of adherent neutrophil detachment from the endothelium, promoting their reentry into the circulation. Taken together, our results demonstrate that PARS inhibition reduces local and systemic inflammation. Part of the antiinflammatory effects of PARS inhibition is due to reduced neutrophil recruitment, which may be related to maintained endothelial integrity.

Animals↗
PubMed1997

Detection of dengue virus from field Aedes aegypti and Aedes albopictus adults and larvae.

Mosquito adults and larvae were collected from dengue high risk areas and transported to the laboratory for identification. Identified mosquitos were pooled according to the species, date and locality and stored at -70 degrees C. A total of 1,385 pools of Aedes albopictus and 267 pools of Ae. Aegypti were collected from major towns in 12 states in Peninsular Malaysia. Virus isolation was carried out using cell culture (C6/36 clone) of Ae. albopictus and detection of dengue virus by the peroxidase anti-peroxidase staining. All positive isolations were further re-confirmed by the reverse transcriptase-polymerase chain reaction (RT-PCR). Most of the pools were negative with PAP staining and RT-PCR. However, 11 mosquito pools were positive with PAP staining. On the other hand, samples from Terengganu, Pulau Pinang and Johor were positive using both methods.

Adult↗
PubMed1996

A new video path analyzer to monitor travel distance, rearing, and stereotypic movement of rats.

A new video path analyzer, described herein, monitors travel distance, rearing, stereotypic movement, rotation, and speed of rats simultaneously. The video path analyzer was equipped with a cage (black background, 50 cm long x 50 cm wide x 50 cm high), camera, television screen, computer, and printer. A detailed description of this equipment is included. While studying the known activating effects of d-amphetamine on rats' behavior, we also evaluated the equipment for its maximum and accurate contribution to this study. Results indicate that this equipment compared to photocell equipment produced reliable data and offered the advantages of lower cost. It is expected to gain more popularity in the near future.

Animals↗
PubMed1994

Difference in extracellular cocaine concentration between the ventral tegmental area and the medial prefrontal cortex following intravenous administration as revealed by quantitative microdialysis coupled with in vivo calibration.

Two microdialysis probes (active length: 1 mm) were simultaneously lowered into the ventral tegmental area (VTA) and the medial prefrontal cortex (mPFC) of each male, adult Sprague-Dawley rat, anesthetized with chloral hydrate, to evaluate whether cocaine distribution between these two areas is uniform after i.v. injection of 3 mg/kg cocaine. Using a modified in vivo calibration method, we can estimate the extracellular cocaine concentration in those nuclei. This proposed calibration method offers the advantages of simplicity and speed. Measurement of the cocaine concentration in the dialysate and estimation of the extracellular cocaine concentration showed that extracellular cocaine in the VTA was significantly higher than that in the mPFC. Next, the active length of the dialysis probe was extended to 4 mm in order to examine the effect of the active probe length on the cocaine distribution profile between the mPFC and a mixed area of VTA and red nucleus. Surprisingly, the cocaine concentration in dialysate had a contradictory result compared to the extracellular cocaine concentration due to in vivo recovery in the mPFC (25.3 +/- 3.1%) which was significantly higher than that in the mixed area (17.5 +/- 1.6%). Firstly, these results suggest that distribution of cocaine following systemic administration was not uniform in the rat brain. Secondly, in a valid comparison of drug concentrations between the two dialysis areas, we must consider the in vivo recovery for each brain region.

Animals↗
PubMed1994

Obesity in preschool children: an intervention programme in primary health care in Singapore.

The Programme on Prevention and Management of Obesity in Preschool Children, aged three to six years, was implemented in 17 Primary Health Clinics in November 1991. The study sample comprised 1128 preschool children who qualified to enter the obesity register, using the defined criteria for obesity of 2 standard deviations above the normal weight for height and age. This group was divided into three categories, namely, mildly overweight (120% to below 140%), moderately overweight (140% to below 160%), and severely overweight (above 160%). The severely overweight category was referred to dietitians for follow-up management, while the other two categories were managed by the clinic staff through pre-planned nurse-conducted counselling sessions. In this paper, we analysed the first 1128 preschool children aged three to six years on the Programme with respect to their demographic characteristics; medical conditions; family history of obesity, diabetes, hypertension and ischaemic heart disease; number of siblings and parents' educational and occupational status. The Malay children showed significantly more severe grades of obesity compared to the Chinese and Indian children. A family history of obesity and hypertension among the three groups were significant (P < 0.001). After one year of follow-up with the intervention programme, the following were found: 40.4% (456) of the children improved in their obesity status and 20.2% (228) reached normal status. The severe, moderate and mild categories reduced from 6.3% to 5.9%, 29.3% to 23.2% and 64.4% to 50.7% respectively and was found to be statistically significant (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1993

Associated injuries in facial fractures: review of 839 patients.

Patients with facial trauma may have associated injuries requiring immediate or specialised attention. This paper reports the incidence and nature of significant associated neurosurgical, ocular, spinal, torso and extremity injuries in facial fracture patients treated by the Department of Plastic and Reconstructive Surgery from June 1989 to June 1992. Of 839 patients treated during the period, 95 patients (11.3%) sustained significant concomitant injuries outside the facial skeleton. There were 45 (5.4%) patients with associated neurosurgical injuries, 33 (3.9%) with ocular injuries, 8 (0.9%) with spinal injuries, 16 (1.9%) with injuries of the torso, and 62 (7.4%) with injuries of the extremities. The spectrum of the injuries is presented. Most neurosurgical injuries are a result of focal impact and the intervention required is related mainly to local fracture management and the repair of dural tears. The risk of significant ocular injury is highest when the fracture involves the orbit. Injuries of the spine, torso (chest, abdomen, pelvis), and limbs were seen mainly in road trauma patients.

Abdominal Injuries↗
PubMed1993

Sports-related facial fractures: a review of 137 patients.

One hundred and thirty-seven patients with sports-related facial fractures were reviewed. These made up 16.3% of 839 patients with facial fractures seen at the Department of Plastic and Reconstructive Surgery, Royal Adelaide Hospital, between June 1989 and June 1992. Males made up 93.4% of patients and 89.1% were aged below 35 years. There was an intent to injure in 11%. Australian Rules football was the causative sport in 52.6%, all the injuries being the result of human contact. Orbitozygomatic fractures were the most frequently observed overall (62%) as well as in Australian Football (58.3%). Cricket contributed to 14.6%, the ball being the agent of injury in all but one of the patients. Horse-riding injuries were the most severe. 89.1% of the patients required surgery and hospital stays ranged from 0 to 18 days with an average stay of 4.7 days. Sports activities, although a significant source of enjoyment, are a significant cause of facial fractures with their attendant morbidity.

Adolescent↗
PubMed1990

A comparative study of two methods for the isolation of human leucocytes for DNA extraction.

The 'Dextran' and the 'Buffy-coat' methods for isolation of human leucocytes for DNA extraction were compared on the basis of DNA yield from the same amounts (10 ml) of blood. Human leucocytes from a total of 11 samples were isolated using both methods for each sample after which DNA was extracted. Extracted DNA samples were treated with ribonucleases and proteinase K after which the yields were quantitated by measuring absorbance at 260 nm. The 'Buffy-coat' method yielded a mean concentration of DNA of 476.7 micrograms/ml (range: 212 to 700 micrograms/ml) while the 'Dextran' method yielded 188.4 micrograms/ml (range: 64 to 340 micrograms/ml). The difference was confirmed by subjecting the extracted DNA samples to agarose gel electrophoresis.

Blood Cells↗