Biomedical subjects

H H Lim

Publications and source records attributed to H H Lim.

At least 19 recordsLinked to original sources

PubMed2005

Tophaceous gout causing atlanto-axial subluxation mimicking rheumatoid arthritis: a case report.

This is a case report of an extremely rare condition of atlanto-axial subluxation secondary to gouty arthritis, which mimicked rheumatoid arthritis at presentation. Gouty arthritis involving the spine is a rare condition. We highlight a case of gouty arthritis involving the atlanto-axial joint resulting in joint instability, subluxation, and neurological deficit. A 66-year-old obese woman who had a polyarticular disease for the previous 3 years presented with neck pain and progressive neurology. A 2-stage procedure was performed: posterior decompression and occipitocervical fusion followed by further anterior trans-oral decompression. However, after an initial neurological improvement, she succumbed to aspirational pneumonia and septicaemia. Atlanto-axial subluxation caused by gouty arthritis can present in the same way as rheumatoid arthritis. Therefore, the possibility of this as a differential diagnosis should be kept in mind.

Aged↗

PubMed2004

Coronal plane and apical vertebral rotation correction of adolescent idiopathic scoliosis with multisegmented hook-rod system--a retrospective review.

Between April 1998 and December 1999, thirty patients with Idiopathic Scoliosis were operated with Multisegmented Hook-Rod System. These patients were operated at the mean age of 16 years and were followed up for a mean of 22.3 months (range 13-34 months). Seven patients had anterior release to increase the curve flexibility followed by second stage posterior instrumentation on the same day. The average operating time for a posterior instrumentation alone and anterior release combined with posterior instrumentation were 270 minutes and 522 minutes respectively. The average blood loss was 2.2 litres for posterior instrumentation alone and 3.3 litres for single day anterior release and posterior surgery. The mean preoperative Cobb's angle was 70 degrees. The mean immediate postoperative and final follow up Cobb's angles were 38 and 42 degrees, which represented an average coronal plane correction of 46.7% and 40.0% respectively. The mean preoperative apical vertebral rotation was 25 degrees, which improved to 15 degrees after the operation. At final follow up, the mean apical vertebra rotation was 20 degrees, which represented a mean apical vertebral rotation correction of 20%. Complications of the procedure included one transient neurological deficit, one infection, one graft site infection and one case of screw cut out. We were able to obtain satisfactory correction of idiopathic scoliosis with the Multisegmented Hook-Rod System.

Adolescent↗

PubMed2003

EMLA cream versus dorsal penile nerve block for postcircumcision analgesia in children.

We conducted a prospective, randomized, double-blinded trial comparing preoperative application of EMLA cream and sodium chloride solution dorsal penile block (n = 31) with placebo cream and bupivacaine dorsal penile nerve block (n = 32) for postcircumcision analgesia. Pain was assessed using modified Children's Hospital of Eastern Ontario Pain Scale and the duration of block by the time to requirement of first dose of postoperative analgesic. There was no difference in Children's Hospital of Eastern Ontario Pain Scale between the two groups, but bupivacaine dorsal penile nerve block resulted in longer analgesia (P = 0.003). There were no local or systemic complications related to either technique, and there was a very small incidence of vomiting. We conclude that preoperative application of EMLA cream is an effective and simple method to produce postcircumcision analgesia with a very small incidence of adverse effects.

Acetaminophen↗

PubMed2003

Predicting significant hyperbilirubinaemia and early discharge for glucose-6-phosphate dehydrogenase deficient newborns.

INTRODUCTION: This study aims to assess the usefulness of day 3 (49 to 72 hours) pre-phototherapy total serum bilirubin (TSB) in predicting subsequent significant hyperbilirubinaemia (SHB) and the feasibility of early discharge for term and near-term glucose-6-phosphate dehydrogenase (G6PD) deficient newborns. MATERIALS AND METHODS: This prospective cohort study involved in born G6PD deficient neonates who were > or = 35 weeks and weighted > or = 2000 g at birth. TSB levels and phototherapy requirements in their first two weeks of life were studied. Day 3 pre-phototherapy TSB in the subgroup weighing > or = 2500 g at birth was analysed for its value in predicting subsequent SHB. RESULTS: Of the 129 neonates, 58 (45%) required phototherapy in the first week. Of these, only 4 patients (3.1%) needed phototherapy to be restarted in the second week. Seventy-one (55%) neonates did not require phototherapy at all. In the absence of SHB in the first week, the probability of its development in the second week was zero (95% confidence interval, 0 to 0.057). In the subgroup weighing > or = 2500 g at birth, day 3 pre-phototherapy TSB < or = 154 umol/L predicted no measurable risk of subsequent SHB (sensitivity, 100%; 95% confidence interval, 91.4% to 100%; negative predictive value, 100%; 95% confidence interval, 86.7% to 100%). CONCLUSIONS: G6PD deficient newborns without SHB in their first week of life were at no measurable risk of its development in the second week. Day 3 pre-phototherapy TSB in the subgroup weighing > or = 2500 g was useful for predicting the risk of subsequent SHB. Low-risk infants, thus identified, may be eligible for discharge on or before day 7 of life. Evidence-based early discharge can decrease the social and financial burden of G6PD deficiency in Singapore.

Awards and Prizes↗

PubMed2002

Respiratory conditions in Malaysian asbestos cement workers.

A cross-sectional study was conducted to determine the prevalence and type of respiratory conditions including asbestos-related diseases among Malaysian asbestos cement workers. The study population consisted of 1164 workers who had undergone medical surveillance from 1995 to 1997, including full history, physical examination, chest radiography and spirometry. More than half the male workers were smokers or ex-smokers, with smokers having more respiratory symptoms and signs, and reduced FEV1 compared with non smokers. The five most common respiratory conditions diagnosed were bronchial asthma, chronic bronchitis, pulmonary tuberculosis, upper respiratory tract infections and allergic rhinitis. On follow-up, there were also two cases of asbestosis and one case of bronchial carcinoma. The asbestosis cases were probably related to heavy occupational exposure to asbestos fibres in the past, before governmental regulations were gazetted in 1986. Further follow-up is essential for continued monitoring of the health status of asbestos workers.

Adolescent↗

PubMed2001

Analysis of proteoglycan gene messages in human nasal mucosa and nasal polyp using dot blot hybridization.

It has been suggested that the formation and growth of nasal polyp require the remodeling of extracellular matrix. Proteoglycans (PGs) are major components of the extracellular matrix that maintain the integrity of structural tissue. The leucine-rich repeat PGs include lumican, decorin and biglycan and have many important biologic activities in various pathologic conditions, including the remodeling of the extracellular matrix. Therefore, these small-PG families may be involved in the formation and growth of nasal polyp. In the present study, surgical specimens of nasal polyps and nasal mucosa were assessed for expression of mRNA coding for lumican, decorin and biglycan using reverse transcriptase-polymerase chain reaction followed by dot blot hybridization. Lumican, decorin and biglycan mRNA were expressed in all tissue samples examined. Semiquantitative dot blot hybridization revealed that the levels of the lumican and biglycan messages are lower in nasal polyp tissues than in nasal mucosa. The decorin messages in nasal polyp were expressed at levels similar to those in nasal mucosa. These results suggest that lumican, decorin and biglycan may be important components of the extracellular matrix in nasal mucosa. Considering the function of these PGs, normal levels of decorin associated with low levels of biglycan and lumican may play a role in the pathogenesis of nasal polyposis.

Adult↗

PubMed2001

Early expressed Clb proteins allow accumulation of mitotic cyclin by inactivating proteolytic machinery during S phase.

Periodic accumulation and destruction of mitotic cyclins are important for the initiation and termination of M phase. It is known that both APC(Cdc20) and APC(Hct1) collaborate to destroy mitotic cyclins during M phase. Here we show that this relationship between anaphase-promoting complex (APC) and Clb proteins is reversed in S phase such that the early Clb kinases (Clb3, Clb4, and Clb5 kinases) inactivate APC(Hct1) to allow Clb2 accumulation. This alternating antagonism between APC and Clb proteins during S and M phases constitutes an oscillatory system that generates undulations in the levels of mitotic cyclins.

Anaphase-Promoting Complex-Cyclosome↗

PubMed2001

Traumatic posterior rotatory fracture-dislocation of lumbo-sacral spine.

Fracture-dislocation of the lumbo-sacral spine was an unusual injury and was divided into anterior, posterior and lateral types depending on the displacement of the cephalad portion of the spine over the caudal portion. According to the authors' knowledge, only 31 cases of traumatic fracture-dislocation of the lumbo-sacral spine were reported in the English literature. Only 3 previous reports referred to this injury with a posterior displacement, which was an even rarer injury. This was the fourth report of this type of injury.

Accidents, Occupational↗

PubMed2001

Dynamic measurement of axial vertebral rotation and rotational flexibility in scoliosis by flouroscopic method.

The Pedriolle torsion meter is an established method of vertebral rotation assessment in scoliosis. However, the assessment of scoliosis by this method is static and indirect. The objective of this study is to compare the accuracy of a direct method of assessing scoliosis rotation by fluoroscopy compared to the Pedriolle torsion meter. Secondly, to determine that vertebral body rotation changes with supine posture compared to erect position. Eight volunteers with idiopathic scoliosis were assessed for the apical vertebral rotation with this method and the Pedriolle torsion meter. These patients were also assessed in the supine and erect position with the fluoroscopic method to determine if the apical vertebral rotation would change with posture. The mean Cobb angle of the curves was 62.8 degrees (range 45 degrees to 86 degrees). The mean apical vertebral rotation in a standing position was assessed to be 21.5 degrees by Pedriolle torsion meter and 29 degrees by the fluoroscopic method. This difference was not statistically significant by the student t-test. In most patient, the rotation of vertebrae improved by a varying degree ranging from none to 24 degrees in the supine position. In conclusion, the fluoroscopic method is an alternate mean of measuring vertebrae rotation in idiopathic scoliosis, with comparable accuracy to the Pedriolle torsion meter method. The amount of vertebral rotation changes with posture of the patient.

Adolescent↗

PubMed2001

Intercostal nerve neurotization of the femoral nerve in patients with paraplegia--an anatomical feasibility study.

Neurotization of the brachial plexus is an established procedure in the upper limb. However, neurotization of the lower limb remains experimental. Brunelli reported the use of the ulnar nerve to neurotize the lower limb. Zhao et al reported the use of intercostals nerve to neurotize the lower limb in rats. The aim of the study was to determine the feasibility of using intercostals nerve to neurotize the femoral nerve in human cadavers and to ascertain the ideal intercostals nerve that has the anatomical course that suit this role. Six fresh cadaveric dissection were performed through an extensile midline incision in the postmortem room and the lower six (T7-T12) were identified and traced from their origin. Their length and course identified and charted. T9 and T10 intercostal nerve was thought to be the most suitable nerve as the donor nerve, and the T11 and T12 intercostal nerve could not be free from its intra-muscular course sufficiently to be use as donor.

Feasibility Studies↗

PubMed2001

Delayed decompression of chronic C1C2 subluxation in a pediatric patient with tetraplegia--is recovery possible?

A 2 year-old Malay girl was admitted to our institution with a chesty cough and breathlessness but later found to have a chronic C1/C2 subluxation for one and half year with tetraplegia. Her cervical cord was decompressed and occipito-cervical fusion performed. Her neurological status improved significantly post-operatively and is able to care for her personal hygiene. The authors believe that the ability of the cervical cord to recover in the paediatric age group is remarkable that surgical option should be considered even when all seen lost. We believe that this is the first report in the literature to support this potential.

Cervical Vertebrae↗

PubMed2000

Changes in cochlear electrical stimulation induced Fos expression in the rat inferior colliculus following deafness.

Fos immunoreactive (IR) staining was used to examine changes in excitatory neuronal activity in the rat inferior colliculus (IC) between normal hearing and 21 day deaf rats evoked by basal or apical monopolar cochlear electrical stimulation. The location of evoked Fos IR neurons was consistent with expected tonotopic areas. The number of Fos IR cells increased as stimulation intensity increased in both normal and 21 day deaf animals. Stimulation at 1. 5x threshold evoked fewer Fos IR cells in 21 day deafened animals compared to normal hearing animals. At 5x and above, however, significantly increased numbers of Fos IR neurons (in a larger grouping) were evoked in 21 day deafened animals compared to normal hearing animals. Another group of animals had 7 days of deafness followed by 14 days of chronic basal cochlear electrical stimulation. In this group basal monopolar stimulation at 5x evoked not only a greater number of Fos IR neurons, compared to normal hearing animals, but the location of their grouping was slightly shifted to a more dorso-lateral region in the contralateral IC, compared to the normal hearing and 21 day deaf groups. These observations indicate that both deafness and chronic electrical stimulation may alter central auditory processing.

Animals↗

PubMed2000

Exit from mitosis in budding yeast: biphasic inactivation of the Cdc28-Clb2 mitotic kinase and the role of Cdc20.

Cdc20, an activator of the anaphase-promoting complex (APC), is also required for the exit from mitosis in Saccharomyces cerevisiae. Here we show that during mitosis, both the inactivation of Cdc28-Clb2 kinase and the degradation of mitotic cyclin Clb2 occur in two steps. The first phase of Clb2 proteolysis, which commences at the metaphase-to-anaphase transition when Clb2 abundance is high, is dependent on Cdc20. The second wave of Clb2 destruction in telophase requires activation of the Cdc20 homolog, Hct1/Cdh1. The first phase of Clb2 destruction, which lowers the Cdc28-Clb2 kinase activity, is a prerequisite for the second. Thus, Clb2 proteolysis is not solely mediated by Hct1 as generally believed; instead, it requires a sequential action of both Cdc20 and Hct1.

Anaphase↗

PubMed2000

Cdc20 protein contains a destruction-box but, unlike Clb2, its proteolysisis not acutely dependent on the activity of anaphase-promoting complex.

Both chromosome segregation and the final exit from mitosis require a ubiquitin-protein ligase called anaphase-promoting complex (APC) or cyclosome. This multiprotein complex ubiquitinates various substrates, such as the anaphase inhibitor Pds1 and mitotic cyclins, and thus targets them for proteolysis by the 26S proteasome. The ubiquitination by APC is dependent on the presence of a destruction-box sequence in the N-terminus of target proteins. Recent reports have strongly suggested that Cdc20, a WD40 repeat-containing protein required for nuclear division in the budding yeast Saccharomyces cerevisiae, is essential for the APC-mediated proteolysis. To understand the function of CDC20, we have studied its regulation in some detail. The expression of the CDC20 gene is cell-cycle regulated such that it is transcribed only during late S phase and mitosis. Although the protein is unstable to some extent through out the cell cycle, its degradation is particularly enhanced in G1. Cdc20 contains a destruction box sequence which, when mutated or deleted, stabilizes it considerably in G1. Surprisingly, we find that while the inactivation of APC subunits Cdc16, Cdc23 or Cdc27 results in stabilization of the mitotic cyclin Clb2 in G1, the proteolytic destruction of Cdc20 remains largely unaffected. This suggests the existence of proteolytic mechanisms in G1 that can degrade destruction-box containing proteins, such as Cdc20, in an APC-independent manner.

Amino Acid Motifs↗

PubMed2000

Expression of human beta-defensin 1 mRNA in human nasal mucosa.

Antimicrobial peptides are cationic proteins that are found in a wide range of organisms. Recent reports suggested that human beta-defensin 1 (hBD-1), a prominent group of antimicrobial peptides, is an important component of the innate immune response, particularly at mucosal surfaces that are vulnerable to colonization by potential pathogens. Therefore, hBD-1 may participate in providing intrinsic nasal mucosal defence against microbial infections. The present study aimed to look for hBD-1 mRNA in human nasal mucosa without obvious signs of inflammation. Total RNA was isolated from human inferior turbinate mucosa and hBD-1 mRNA was detected in these tissues by using reverse transcription and polymerase chain reaction (RT-PCR). By in situ hybridization, hBD-1 mRNA was predominantly localized in superficial epithelial cells and submucosal glandular epithelium of human inferior turbinate mucosa. These data suggest that nasal epithelia and submucosal glands may secrete hBD-1, contributing to the mucosal defences of the nose.

Defensins↗

PubMed2000

The use of intravenous atropine after a saline infusion in the prevention of spinal anesthesia-induced hypotension in elderly patients.

UNLABELLED: We investigated the efficacy of IV atropine for preventing spinal anesthesia-induced hypotension in elderly patients. Seventy-five patients undergoing transurethral prostate or bladder surgery were randomized to receive either placebo (n = 25), atropine 5 microg/kg (small-dose atropine, n = 25) or atropine 10 microg/kg (large-dose atropine, n = 25) after the induction of spinal anesthesia. All the patients received an IV infusion of 10 mL/kg 0.9% normal saline over 10 min before the induction of anesthesia. The systolic blood pressure decreased in all three groups after spinal anesthesia. There was a significant increase in the mean heart rate in both atropine groups as compared to the placebo group (placebo group: 78 bpm, 95% confidence interval [CI]: 76.6-78.5; small-dose atropine group: 86 bpm, 95% CI 83.9-88.8; large-dose atropine group: 97 bpm, 95% CI 94.5-100.3; P: = 0.001). There was a significant decrease in the incidence of hypotension in patients who received atropine (placebo group: 76%, small-dose atropine group: 52%, large-dose atropine group: 40%, P: = 0.03). The mean dose of ephedrine required was significantly decreased in the atropine groups (placebo group: 12.2 mg [SD= 10.5], small-dose atropine group: 7.4 mg [SD= 10.0], large-dose atropine group: 5.4 mg [SD= 8.7 mg], P: = 0.048). The total amount of IV fluid and number of patients requiring metaraminol in addition to 30 mg of ephedrine were not significantly different among the three groups. Significant side effects, such as confusion, ST segment changes or angina were not detected in any of the patients. We conclude that IV atropine may be a useful supplement to the existing methods in preventing hypotension induced by spinal anesthesia. IMPLICATIONS: IV atropine increases heart rate in a dose-dependent manner in elderly patients undergoing spinal anesthesia. It reduces the incidence of hypotension and the dose of ephedrine required. Small-dose atropine may be a useful supplement in preventing spinal anesthesia-induced hypotension in elderly patients.

Aged↗

PubMed2000

Expression patterns of p27Kip1 and Ki-67 in cholesteatoma epithelium.

OBJECTIVES: The cell cycle must be involved in cell proliferation of the epithelium of middle ear cholesteatoma Cyclins and cyclin-dependent kinase (CDK) complexes have important regulatory roles during cell cycle progression. Cyclin-CDK complexes are in turn regulated by the cyclin-dependent kinase inhibitors (CDKIs), which generally inhibit cell cycle progression. One of the important CDKI members is p27(Kip1). The goal of this study is to evaluate the expression of p27(Kip1) and Ki-67, a proliferation marker, in cholesteatoma and in the skin of the external ear canal. METHODS: The expressions of p27(Kip1) and Ki-67 in cholesteatoma epithelium (n = 20) and ear canal epithelium (n = 7) were investigated by an immunohistochemical technique. RESULTS: In cholesteatoma epithelium specimens, the expression of p27(Kip1) was observed from the parabasal layer to the granular layer, but not in the basal layer. Ki-67 was expressed dominantly in the basal and parabasal cell layers. Their expressions tend to be increased compared with their expressions in the normal ear canal skin. The expression pattern of the proliferation marker Ki-67 in the epithelial layers of two groups was inversely related to the expression of p27(Kip1). CONCLUSIONS: In cholesteatoma, the expressions of CDKI and Ki-67 were both increased in this study. The ability to inhibit proliferative activity was also increased in the cholesteatoma epithelium. The expression pattern of the proliferation marker Ki-67 in the epithelial layers was inversely related to the expression of p27(Kip1). Not only is the proliferation activity increased, but also the ability to inhibit hyperproliferation is increased in the cholesteatoma epidermis. Despite increased proliferative activity in the cholesteatoma epidermis, epithelial cells still retain the capability to prevent cell cycle arrest by means of p27(Kip1).

Cell Cycle Proteins↗

PubMed2000

Olfactory mucosal findings in patients with persistent anosmia after endoscopic sinus surgery.

Sixty-three biopsy specimens were obtained from the olfactory region of 15 patients with persistent anosmia and 6 patients with normosmia after sinus surgery. Immunohistochemical examination of all specimens with microtubule-associated protein 5 (MAP5) antisera demonstrated olfactory epithelium in 11 of 18 specimens from normosmic patients and in 12 of 45 samples from anosmic patients. There was a significant difference in the proportion of specimens containing olfactory epithelium between the two groups of patients. In normosmic patients, most of the biopsy samples contained normal-appearing olfactory tissue. However, 2 main patterns of histologic findings were noted in the olfactory mucosa of anosmic patients. First, the olfactory receptor cells were remarkably decreased in number. Second, the orderly arrangement of cells characteristic of normal olfactory epithelium was lost, demonstrating a degenerative appearance. These data suggest that olfactory epithelium can be degenerated even in chronic sinusitis and thereafter extensively replaced with respiratory epithelium, resulting in increased sampling error. Moreover, an unimproved olfactory deficit after sinus surgery may be due to the abnormalities observed at the olfactory epithelium level.

Adolescent↗