Search PubMed⌕ Search

Biomedical subjects

M H Tan

Publications and source records attributed to M H Tan.

At least 37 records · Page 2Linked to original sources
PubMed2001

The penetration of 0.005% fluticasone propionate ointment in eyelid skin.

BACKGROUND: The use of corticosteroids to treat periorbital dermatoses carries significant risk of serious side effects such as glaucoma, cataracts, and blindness. Studies to assess levels of corticosteroid penetration in the eyelid are lacking. OBJECTIVE: We assessed corticosteroid penetration in eyelid skin in vitro to obtain information leading to the establishment of safer dosing regimens. METHODS: Fluticasone propionate ointment, 0.005%, was applied (approximately 2-5 mg/cm(2)) to samples of human eyelid skin, and penetration was assessed by using modified Franz diffusion cells. Drug concentration was determined at 12, 24, 36, and 48 hours after application by liquid chromatography tandem mass spectrometry. RESULTS: Only very small amounts of fluticasone propionate penetrated the skin (range, 0.618% +/- 0.339% to 1.467% +/- 0.695%). CONCLUSION: Further studies are warranted to examine the safety and efficacy of 0.005% fluticasone propionate ointment for the treatment of eyelid dermatoses.

Administration, Topical↗
PubMed2001

Progressive ulnar neuropathy caused by delayed migration of a foreign body.

Foreign bodies in the hand can cause a variable degree of acute or delayed injuries to the important structures. We report a rare case of a progressive ulnar neuropathy caused by delayed migration of a foreign body in the forearm. Ultrasonographic localisation and surgical removal of the foreign body resulted in gradual recovery of neurological function.

Adult↗
PubMed2001

Improvement of Pyoderma gangrenosum and psoriasis associated with Crohn disease with anti-tumor necrosis factor alpha monoclonal antibody.

BACKGROUND: Infliximab is an anti-tumor necrosis factor alpha monoclonal antibody IgG effective in the treatment and maintenance of remission of active refractory Crohn disease and associated draining enterocutaneous fistulae. Multiple infusions of infliximab show promising results in patients with rheumatoid arthritis. Currently, there is limited clinical experience with infliximab, and no published reports exist on its use in cutaneous disorders. OBSERVATIONS: We describe 2 patients with Crohn disease and pyoderma gangrenosum and 1 patient with Crohn disease and psoriasis who were treated with infliximab for recalcitrant Crohn fistulae, with concurrent improvement in their skin diseases. CONCLUSIONS: These cases suggest that infliximab, a promising therapeutic agent for refractory Crohn disease and fistulae, may also be effective in the treatment of pyoderma gangrenosum and psoriasis associated with Crohn disease.

Adult↗
PubMed2000

Current treatment of insulin resistance in type 2 diabetes mellitus.

The two major metabolic perturbations resulting in hyperglycaemia in type 2 diabetes are insulin resistance and insulin deficiency. Insulin resistance occurs in peripheral organs (muscle and fat), leading to decreased glucose uptake and utilisation, and in liver, leading to increased hepatic glucose production. Thiazolidinediones, pharmacological ligands for PPAR gamma, can modulate the expression of genes influencing carbohydrate and lipid metabolism. Pioglitazone, a recently introduced thiazolidinedione, improves glycaemic control and lipid profiles in people with type 2 diabetes. Some of the possible mechanisms of improving glycaemic control include (a) increase in GLUT-1 and GLUT-4, (b) enhancement of insulin signalling, (c) decrease in tumour necrosis factor-alpha action, (d) reduction in plasma free fatty acid and (e) decrease in PEPCK. Together these can increase glucose uptake and utilisation in the peripheral organs and decrease gluconeogenesis in the liver. Possible mechanisms resulting in more desirable lipid profiles include an increase in phosphodiesterase-3B resulting in reduced intra-cellular lipolysis in adipocytes and an increase in lipoprotein lipase resulting in enhanced clearance of triglyceride-rich lipoproteins(TRLs). Pioglitazone, used as monotherapy or in combination with sulphonylurea, biguanide or insulin, improves glycaemic control, lowers serum triglycerides and raises high density lipoprotein (HDL)-cholesterol. It enhances hepatic and peripheral insulin sensitivity. In clinical trials, there has been no evidence of hepatotoxicity or increased incidence of elevated serum ALT in subjects taking pioglitazone compared with placebo.

Diabetes Mellitus, Type 2↗
PubMed1999

Elevation of high-density lipoprotein cholesterol in humans during long-term therapy with amiodarone.

The distribution of plasma lipids was studied in 18 patients receiving amiodarone for 18 months, confirming that amiodarone is associated with a 17% elevation in total cholesterol and, for the first time, documenting increases in high-density lipoprotein cholesterol. The increase in high-density lipoprotein was proportionately greater than that of low-density lipoprotein cholesterol, suggesting that the impact of changes in the predicted risk of coronary heart disease are less important than if the elevation consisted of low-density lipoprotein cholesterol alone.

Adult↗
PubMed1999

Relation of genetic polymorphisms of apolipoprotein E, angiotensin converting enzyme, apolipoprotein B-100, and glycoprotein IIIa and early-onset coronary heart disease.

OBJECTIVE: Apolipoprotein E (APOE) E4, apolipoprotein B-100 (APOB) Q3611 allele, the angiotensin converting enzyme (ACE) deletion (D) allele and glycoprotein IIIa (GP3A) P33 mutant allele are reported to predispose to early-onset coronary heart disease (CHD). These associations were not all confirmed in more recent studies. To determine the impact of these alleles on CHD, we examined the prevalence of these mutations in patients presenting with early-onset CHD and compared them to those manifesting CHD later in life. The delayed-onset was considered a sign of longevity and would serve as a comparative group to assess prevalence of the biochemical and genetic risk factors. METHODS: 300 patients with a history of myocardial infarction or angina pectoris and angiographically documented CHD were studied. Patients were divided into two groups: group 1 (G1 = 150 patients) presenting with these findings under the age of 50 years; while group 2 (G2 = 150 patients) were patients presenting for the first time over the age of 65 years. Prevalence of the alleles of APOE, APOB, ACE and GP3A was assessed by molecular analysis. An association of any of these genotypes with early onset CHD could lead to a higher prevalence in the younger age group. RESULTS AND CONCLUSIONS: None of the suspected alleles namely APOB Q3611 [G1: 10.7% vs. G2: 9.0%, p = 0.57], ACE D (G1: 52.0% vs. G2: 49.7%, p = 0.57), or the GP3A P33 (G1: 17.3% vs. G2: 15.7%; p = 0.58) showed any significant difference between the two groups. Subjects with APOE E4 were more frequent in the younger age group (G1: 18.3% vs. G2: 13.7%; p = 0.047), while APOE E2 was more frequent in G2 (G2: 10.0% vs. G1: 2.7%; p = 0.0002). Multivariate analysis showed an odds ratio of APOE E2 allele in G1 of 0.27 with a confidence interval of 0.10-0.73.

Adult↗
PubMed1998

A novel mutation in Exon 4 of the low density lipoprotein receptor gene resulting in heterozygous familial hypercholesterolemia associated with decreased ligand binding.

Familial hypercholesterolemia (FH) is an autosomal dominant disorder caused by mutations in the low density lipoprotein (LDL) receptor gene. Currently, diagnosis of heterozygous FH relies on clinical phenotype; however, the use of clinical criteria for the diagnosis of heterozygous FH does not always permit unequivocable diagnosis of the disease. Molecular diagnosis of FH is clinically valuable especially in regions where founder mutations exist or where polygenic hypercholesterolemia is prevalent. In this paper we report the identification of a novel mutation, a cytosine to guanine substitution, at codon 152 in exon 4 of the LDL receptor gene in a Nova Scotian family clinically diagnosed with heterozygous FH. The mutation creates a recognition sequence for the restriction endonuclease BsrI, and can be readily detected by BsrI restriction analysis of a 160 bp amplicon spanning the mutation. This analysis was used to show that the mutation segregated with the disease in this family and is the probable cause of FH in this kindred.

Adult↗
PubMed1998

Staged diabetes management: computerizing a disease state management program.

Recently, the Diabetes Control and Complication Trial (DCCT) and other similar studies have demonstrated that near-normalization of blood glucose in diabetes will reduce complications up to 75% but translation of these results into practice has been difficult. In an attempt to help provide the best possible control of patients with diabetes, we have produced an attempt to help provide the best possible control of patients with diabetes, we have produced a new disease state management system for diabetes, called "Staged Diabetes Management" (SDM), implemented it in over 100 sites worldwide, and developed a computer program to simplify its use. SDM, designed to change the way we deal with patients with diabetes, is based upon five principles: (1) community involvement in setting care guidelines; (2) negotiation of goals with patients; (3) appropriate timelines for therapeutic success; (4) use of flowcharts for medical decisions; and (5) evaluation of the program. SDM is designed to be altered by a community to meet its needs and resources. It encourages primary care physicians to deliver better diabetes care using a team approach and to refer patients with diabetes to specialists when appropriate. It has a complete set of materials for communities, individual health care providers and patients. SDM has been tested for changes in structure, process and outcomes. A meta-analysis of seven clinical trials with over 500 patients has shown a time-weighted average fall in hemoglobin A1c of 1.7 points (equivalent to a drop in mean blood glucose of about 3.5 mM or 60 mg/dL). Preliminary pharmacoeconomic analysis demonstrates a lifetime cost saving of over $27,000 per patient. A computer program has been developed for the Microsoft Windows environment that contains a client-server database, based upon DiabCare, for the data file structure.

Adult↗
PubMed1998

Effect of methimazole, with or without L-thyroxine, on remission rates in Graves' disease.

Medical treatment of Graves' disease involves antithyroid drugs with or without the addition of exogenous T4. There have been conflicting reports as to whether the addition of T4 improves remission rates or delays relapse. To evaluate this issue in a North American population, 199 patients were treated with methimazole until they were euthyroid. They were then randomized to either methimazole alone in a dose sufficient to normalize TSH (group 1), or to 30 mg methimazole daily plus sufficient T4 to maintain TSH in the upper normal range (group 2), or to 30 mg methimazole daily plus sufficient T4 to suppress TSH below 0.6 mIU/L (group 3). After 18 months, methimazole was stopped, and T4 was continued in groups 2 and 3. Because not all patients in groups 2 and 3 achieved their target TSH concentration, they were reassigned to group A (TSH > or = 1.0) or group B (TSH < 1.0), based on the mean TSH achieved during methimazole treatment. One hundred forty-nine patients have been followed for at least 6 months after stopping methimazole (mean 27 months). Fifty-eight percent of patients have relapsed. There were no significant differences in relapse rates after stopping methimazole. Among those patients who did relapse, however, there was a significant difference in the months to relapse after stopping methimazole between groups B and 1 (group 1: 3.3 +/- 0.7, group A: 5.6 +/- 0.8, group B: 7.4 +/- 1.7; P = 0.01 for the comparison between groups B and 1). We conclude that the addition of T4 to methimazole does not improve long-term remission rates in Graves' disease.

Adult↗
PubMed1998

Psoriasis.

Psoriasis is an inflammatory disorder of the skin that involves complex interactions between the dermis and epidermis. There are several forms of psoriasis, the most common being plaque type psoriasis. Other forms include guttate, pustular and erythrodermic psoriasis. Both the skin and joints are affected in this disease. Psoriasis ranges in severity from a few small plaques to involvement of the entire cutaneous surface. Therapy of psoriasis depends on the location, type and severity of the disease. Treatments include a wide array of topical medications including tars, anthralin, topical corticosteroids, vitamin D(3) analogs, retinoids and over-the-counter preparations. Phototherapy with ultraviolet B and PUVA are used for more widespread involvement. Common systemic therapies include methotrexate, retinoids and cyclosporin. This article will review the pathogenesis and clinical features of psoriasis, as well as current and future therapies.

Journal Article↗
PubMed1998

Accuracy of CT-guided needle biopsy of musculoskeletal neoplasms.

OBJECTIVE: The purpose of our study was to assess the accuracy of CT-guided biopsy of musculoskeletal neoplasms with respect to technique, anatomic site, and histology. MATERIALS AND METHODS: During a 3-year period (January 1992 to December 1994), 176 core needle biopsies and 45 fine-needle aspirations were performed under CT guidance on patients with musculoskeletal neoplasms. To assess the accuracy of these procedures, we compared the diagnosis at biopsy with the final diagnosis as determined at the time of definitive treatment of the lesion. All biopsy findings were categorized as a primary malignancy (excluding round cell lesions), round cell lesion, local recurrence, or metastatic carcinoma. In addition, each lesion was analyzed according to which biopsy technique was used, whether frozen tissue section or rapid cytologic evaluation was used, and at which anatomic site the mass was found. RESULTS: The accuracy for needle biopsy was 93% and that for fine-needle aspiration was 80%. The complication rate for both techniques was less than 1%. Accuracy rates for the four categories of primary malignancy, round cell lesion, local recurrence, and metastatic carcinoma were 87%, 75%, 94%, and 100%, respectively. The mismatch rates were similar in soft-tissue lesions (5/52) and bone lesions (16/169). Diminished accuracy was associated with round cell lesions (20%) and lesions located in the spine or the perivertebral region (20%). Nondiagnostic and insufficient specimens were found in 18 (8%) of the 221 patients. CONCLUSION. CT-guided biopsy of musculoskeletal malignancies is a safe and effective procedure if performed by a team of clinicians, pathologists, and radiologists who possess subspecialty expertise.

Biopsy, Needle↗
PubMed1998

Fractional esterification rate of HDL particles in patients with type 2 diabetes. Relation to coronary heart disease risk factors.

OBJECTIVE: To study the fractional esterification rate of cholesterol on HDL particles (FERHDL) in adults with type 2 diabetes and assess its correlation with serum lipids and other coronary heart disease (CHD) risk factors. RESEARCH DESIGN AND METHODS: FERHDL was measured in 90 adult (57 men, 33 women) patients by an isotopic assay method involving several steps, including preparation of VLDL- and LDL-depleted plasma, labeling of the sample with a trace amount of tritiated cholesterol, separation of free and esterified cholesterol fractions by chromatography post incubation, and subsequent counting of radioactivity in the individual fractions. RESULTS: Male patients have higher FERHDL values than their female counterparts. When HDL cholesterol was controlled for in a multivariate regression analysis, the sex factor was not significant. There was a significant positive correlation between FERHDL and plasma total cholesterol (r = 0.32), triglycerides (r = 0.82), apolipoprotein B (apo B; r = 0.48), insulin (r = 0.46), BMI (r = 0.31), and waist-to-hip ratio (WHR; r = 0.50). There was a negative correlation between FERHDL and HDL cholesterol (r = -0.76) and apolipoprotein AI (r = -0.60). When both HDL cholesterol and triglycerides were controlled for, the only significant correlation was between FERHDL and BMI. CONCLUSIONS: Non-insulin-requiring type 2 diabetic patients have FERHDL, which correlated positively with triglycerides and negatively with HDL cholesterol. The positive correlation of FERHDL with serum insulin, WHR, total cholesterol, and apo B, but not that with BMI, loses its significance when HDL cholesterol and triglycerides are controlled. The sex difference between men and women in FERHDL also loses its significance when HDL cholesterol is controlled.

Adult↗
PubMed1998

No relationship between carbohydrate intake and effect of acarbose on HbA1c or gastrointestinal symptoms in type 2 diabetic subjects consuming 30-60% of energy from carbohydrate.

OBJECTIVE: To determine the relationship between carbohydrate intake and the effect of acarbose on HbA1c in subjects with type 2 diabetes treated with acarbose alone, acarbose plus sulfonylurea, acarbose plus metformin, or acarbose plus insulin. RESEARCH DESIGN AND METHODS: We conducted a double-blind randomized placebo-controlled study in which subjects with diabetes in four treatment strata (77 on diet alone, 83 treated with metformin, 103 treated with sulfonylurea, and 91 treated with insulin) were randomized to treatment with placebo or acarbose for 12 months. Before randomization, and 3, 6, 9, and 12 months after randomization, fasting blood was obtained for HbA1c, and 3-day diet records were collected. Subjects who completed at least 6 months of acarbose therapy and provided at least three 3-day diet records were included. RESULTS: In the 114 subjects included in this analysis, carbohydrate intake varied from approximately 30-60% of energy There was no significant relationship between carbohydrate intake and change in HbA1c in any of the four treatment strata (diet: n=26, r=0.35, P=0.076; metformin: n=27, r=0.26, P=0.19; sulfonylurea: n=35, r=0.24, P=0.16; insulin: n=25, r=-0.27, P=0.19). In the 80 subjects consuming <50% of energy from carbohydrate, the fall in HbA1c (7.83 +/-0.17% at baseline to 6.72+/-0.13% on acarbose, P < 0.001) was no different from that of the 34 subjects consuming >50% of energy from carbohydrate (7.55+/-0.25% at baseline to 6.66+/-0.23% on acarbose, P < 0.001). There was no difference in carbohydrate intake between those who dropped out of the study because of gastrointestinal side effects and those who did not, and there was no relationship between severity of symptoms and the composition of the diet. CONCLUSIONS: In subjects with type 2 diabetes consuming 30-60% of energy from carbohydrate, the effect of acarbose on HbA1c and gastrointestinal symptoms was not related to carbohydrate intake. Because most people consume at least 30% of energy from carbohydrate, we conclude that no special diet is needed for acarbose to be effective in improving blood glucose control in the treatment of type 2 diabetes.

Acarbose↗
PubMed1998

An outbreak of rabies in dogs in the state of Terengganu 1995-1996.

The presence of rabies in dogs has been well recognized in areas of Malaysia close to the Thai border but it has rarely ever been reported in Terengganu which is a state on the East Coast of Malaysia. From November 1995 to June 1996 six different rabid stray dogs were found to have been involved in dog bite attacks on 9 members of the public. We report these cases to highlight that rabid dog bites may occur even in areas where the disease is thought to be rate. Medical and veterinary staff must keep the possibility of the risk of rabies in mind when faced with patients who have been bitten by dogs.

Animals↗
PubMed1998

Decompression illness associated with underwater logging: 6 case reports from Kenyir Lake, Malaysia.

The formation of Kenyir Lake as part of a hydroelectric project in the 1980s caused much forest area to be submerged. From 1991, underwater divers were employed to log these sunken trees at depths of up to 100 meters. At least 6 mishaps involving underwater logging personnel were recorded from March 1994 to August 1996. We retrospectively reviewed 5 cases who were managed in Hospital Kuala Terengganu. The patients presented with marked cardiorespiratory and neurological disturbances. One diver died in the Hospital while another died at the recompression chamber. Three divers were treated with recompression and improved. Average delay before the start of recompression was 14 hours. Underwater logging has definite dangers and steps must be taken to ensure that both the divers and the equipment are appropriate for the task. Availability of a nearby recompression facility would greatly enhance the management of diving accidents, not only for commercial divers but also for recreational divers who frequent the islands nearby.

Adolescent↗
PubMed1998

An unusual case of Wegener's granulomatosis.

A 35-year-old Malay man underwent treatment for uveitis of the right eye in 1992 but developed marked visual impairment in the affected eye after he failed to attend follow-up. Two years later, he complained of difficulty swallowing and was found to have left sided X and XI cranial nerve palsies. Chest radiograph showed a cavitating lesion in the lower zone of the right lung field. Inflammation and perforation of the nasal septum was found on examination of his upper respiratory tract. Punch biopsies taken from that area showed chronic inflammatory change and necrotizing vasculities. The patient was diagnosed as having Wegener's granulomatosis and made a very good recovery with immunosuppressive therapy.

Adult↗