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Biomedical subjects

E Tan

Publications and source records attributed to E Tan.

At least 73 records · Page 4Linked to original sources

Pulsed dye laser treatment of spider telangiectasia.

Spider telangiectasia is a common benign vascular malformation which can be a source of cosmetic concern for the patient. A retrospective review of 30 adults and children with spider telangiectasia treated by the flashlamp-pumped pulsed dye laser was undertaken. There was complete clearance of treated spider telangiectasia in 93% of patients after a single treatment. There were no reported permanent adverse effects with purpura being the only transient problem. Most patients were satisfied with the eventual results of treatment and would recommend treatment to other people with a similar problem. This laser should be considered as the treatment of choice for spider telangiectasia.

Adolescent↗

Juvenile spring eruption: a prevalence study.

AIMS: To measure the prevalence of juvenile spring eruption of the ears in Dunedin primary school aged children. To characterise the population of children affected by juvenile spring eruption in New Zealand. METHODS: Children attending three primary schools were examined for evidence of clinical and preclinical juvenile spring eruption on a single occasion in the late spring. Ear protuberance, hair cover and other factors related to sun exposure were assessed. RESULTS: The overall prevalence of clinical juvenile spring eruption was 6.7% (95% confidence interval = 4.7% to 7.5%). The prevalence in males was 12% (95% CI = 7.3% to 17%). Lack of hair cover and protuberant ears (75th percentile or greater) were strongly associated with clinical juvenile spring eruption. There was no evidence of an association between clinical juvenile spring eruption and skin tone, hair colour, time spent outdoors, sunscreen use, and hat use. CONCLUSION: Juvenile spring eruption is a relatively common dermatological condition among primary school aged children in Dunedin, especially boys.

Child↗

Pulsed dye laser treatment of port-wine stains: a review of patients treated in Western Australia.

OBJECTIVE: To assess the effectiveness of the flashlamp-pumped pulsed dye laser in the treatment of port-wine stains. DESIGN: A retrospective review of medical records and patients. SETTING: Royal Perth Hospital (a tertiary referral hospital), August 1989 to December 1992. SUBJECTS: 186 consecutive patients with port-wine stains treated with a flashlamp-pumped pulsed dye laser. OUTCOME MEASURES: Degree of lesion fading; adverse reactions. RESULTS: Of 131 patients who completed treatment, 78% had better than 50% fading of the lesion and only 9% had less than 25% fading. An average 3.4 treatments were needed to achieve more than 50% fading. The response was better in children than in adults, although the difference was not significant. Anaesthesia was needed for 44% of patients. Pigmentary change (usually transient) occurred in 6.1% of patients and permanent and signficiant adverse effects in only 4.6%. CONCLUSION: This study confirms the efficacy of the flashlamp-pumped pulsed dye laser in the treatment of port-wine stains in children and adults. Early treatment of port-wine stains should be encouraged to reduce the physical and psychological morbidity of disfiguring lesions.

Adolescent↗

Vascular effects of metformin. Possible mechanisms for its antihypertensive action in the spontaneously hypertensive rat.

Metformin, an antidiabetic agent, potentiates insulin action and reduces insulin resistance. We examined the antihypertensive effects and vascular effects of metformin in spontaneously hypertensive rats (SHR). Wistar-Kyoto normotensive (WKY) and SHR were injected with metformin (100 mg/kg) or saline subcutaneously twice daily for 4 weeks. Blood pressure was recorded by a tail-cuff plethesmographic method. Metformin treatment significantly attenuated (P < .05) the increase in blood pressure in metformin treated SHR versus untreated control SHR. At the end of the experimental period of 4 weeks, metformin-treated SHR had a mean blood pressure that was 34 mm lower than that of untreated SHR. Metformin treatment had no significant effect on blood pressure in WKY rats. Treatment of SHR aortic smooth muscle (SM) cells with metformin (2 micrograms/mL) for 24 h significantly decreased (P < .05) arginine vasopressin- and thrombin- stimulated increase in [Ca2+]i. However, metformin treatment did not have a significant effect on the basal [Ca+]i. Incubation of SHR aortic SM cells with OH-L-arginine (25 to 100 mumol/L) for 24 h increased nitrite production in a dose dependent manner. Metformin (5 micrograms/mL) treatment of SM cells increased nitrite production at all concentrations of OH-L-arginine; however, differences were significant (P < .05) only at 25 and 50 mumol/L OH-L-arginine. These results suggest that metformin may be decreasing arterial pressure in the SHR, at least in part, by attenuating the agonist-stimulated [Ca2+]i response in SHR vascular smooth muscle cells.

Animals↗

Occupational contact dermatitis to gold.

A case of occupational contact dermatitis to gold is presented. This is uncommon as gold is relatively insoluble. Allergic contact dermatitis to gold is confirmed by patch testing with gold sodium thiosulfate 0.5% in petrolatum. Occupational contact dermatitis in the gold industry can be reduced by providing workers with more protective gear and better ventilation.

Dermatitis, Allergic Contact↗

Pulsed dye laser treatment of port-wine stains. A patient questionnaire.

BACKGROUND: The flashlamp-pumped pulsed dye laser is recognized as the treatment of choice for port-wine stains. Most studies assessing its effectiveness are based on clinical reviews by the treating physician. Each patient's assessment of treatment outcome is also important. OBJECTIVE: To assess the patients' attitudes toward laser treatment, satisfaction with treatment outcome, and reasons for withdrawal from treatment. METHODS: A questionnaire was distributed to 186 patients with port-wine stains treated with the flashlamp-pumped pulsed dye laser. Of the 186 patients, 131 had completed treatment and 55 were having ongoing treatment or had withdrawn from treatment. Replies were received from 164 patients, a response rate of 88%. RESULTS: Most patients expressed satisfaction with the present appearance of their treated port-wine stains. The majority of any adverse effects experienced were transient. Over 90% of patients would recommend treatment to other people with port-wine stains. CONCLUSION: The flashlamp-pumped pulsed dye laser improves the appearance of port-wine stains, and is regarded favorably by patients. Patients' assessments of treatment outcomes correlate well with clinical results obtained.

Adult↗

Uptake of sulfate conjugates by isolated rat hepatocytes.

The uptake of estrone sulfate (E1S; 1 to 400 microM), harmol sulfate (HS; 5 to 900 microM), and 4-methylumbelliferyl sulfate (4MUS; 5 to 1000 microM) was investigated in isolated rat hepatocytes in the presence or absence of inhibitors. Uptake of all of the sulfate conjugates was rapid and exhibited saturation kinetics, best characterized by saturable and nonsaturable (linear transmembrane clearance) transport systems. The KM's were: 16 +/- 6, 123 +/- 28, and 64 +/- 6 microM for E1S, HS, and 4MUS, respectively, with corresponding Vmax's of 0.85 +/- 0.56, 0.48 +/- 14, and 0.42 +/- 0.07 nmol/min/10(6) cells. The nonsaturable uptake clearances, which displayed concentration-independent uptake, were 3 +/- 2, 1 +/- 0.1, 0.5 +/- 0.1 microliter/min/10(6) cells, respectively. Uptake of E1S was inhibited by ouabain (1 mM) and replacement of sodium by choline, whereas HS was insensitive to the addition or substitution. Uptake of both E1S and HS was significantly reduced by metabolic inhibitors (antimycin A, 2.7 microM, rotenone, 30 microM, and KCN, 2 mM) and temperature reduction (from 37 to 27 degrees C). 4,4'-Diisothiocyanostilbene-2-2-'disulfonic acid (2 mM), an inhibitor of anion transport, reduced E1S and HS uptake; E1S uptake was also reduced by HS. HS uptake by both saturable and nonsaturable transport components was depressed by 4MUS (300 microM); the apparent KM was increased by 83% while the Vmax remained unaltered, and the nonsaturable component was decreased by 48%. The data strongly suggest that multiple pathways exist for the uptake of E1S, HS, and 4MUS. E1S uptake is sodium-dependent, requires energy, and is inhibited by anions such as 4,4'diisothiocyanostilbene-2-2'-disulfonic acid and other sulfate conjugates. HS uptake, while being energy dependent, is not sodium dependent, and is inhibited by 4MUS in a competitive fashion. At least one of these pathways is shared.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

Immunosuppressive treatment of motor neuron syndromes. Attempts to distinguish a treatable disorder.

OBJECTIVE: To determine if response to immunosuppressive treatment in motor neuron syndromes could be predicted on the basis of clinical features, anti-GM1 antibodies, or conduction block. DESIGN: Prospective, uncontrolled, treatment trial using prednisone for 4 months followed by intravenous cyclophosphamide (3 g/m2) continued orally for 6 months. SETTING: All patients were referred to university hospital medical centers. PATIENTS: Sixty-five patients with motor neuron syndromes were treated with prednisone; 11 patients had elevated GM1 antibody titers, and 11 patients had conduction block. Forty-five patients received cyclophosphamide, eight of whom had elevated GM1 antibodies and 10 had conduction block. RESULTS: One patient responded to prednisone, and five patients responded to cyclophosphamide treatment. Only patients with a lower motor neuron syndrome and conduction block improved with either treatment. Response to treatment did not correlate with GM1 antibodies. CONCLUSIONS: GM1 antibodies did not serve as a marker for improvement in patients with motor neuron syndrome treated with immunosuppressive drugs. Patients with amyotrophic lateral sclerosis failed to improve irrespective of laboratory findings.

Adult↗

Cerebellar ataxia associated with hypogonadotropic hypogonadism and chorioretinopathy: a poorly recognized association.

We report a male with cerebellar ataxia, hypogonadism and chorioretinopathy. The age of onset was 12. The parents were first cousins. Endocrinologic studies demonstrated hypogonadotropic hypogonadism due to pituitary dysfunction. The ocular disorder involved the choriocapillaris and the retina. The association may represent a separate syndrome, seldom recognized in the past.

Adult↗

Acute renal failure resulting from intravenous immunoglobulin therapy.

In idiopathic thrombocytopenic purpura, a known immune-mediated disorder, intravenous IgG is the treatment of choice. Success and the lack of side effects of intravenous IgG in the treatment of idiopathic thrombocytopenic purpura have encouraged consideration of its use in the treatment of neurologic disorders of presumed autoimmune pathogenesis. In this report, we describe two patients who developed acute renal failure following intravenous IgG treatment. The first patient had chronic inflammatory demyelinating polyneuropathy and was treated with intravenous IgG instead of prednisone because of preexisting diabetes. The second patient had idiopathic thrombocytopenic purpura and received intravenous IgG treatment as part of standard care. The patient with idiopathic thrombocytopenic purpura had unrelated bilateral high-grade renal artery stenosis. Both patients had a creatinine level of 140 mumol/L (1.6 mg/dL) prior to treatment. Renal biopsies performed during acute renal failure in each patient demonstrated marked swelling and vacuolization of the proximal tubular epithelial cytoplasm typical of high-solute-load-induced damage (similar to that associated with the use of mannitol). This report draws attention to the importance of screening for impaired renal function before intravenous IgG therapy is initiated. The patients we describe received standard doses of intravenous IgG at the recommended infusion rate yet developed oliguric renal failure. Awareness of serious side effects and recognition of predisposing factors provide means of avoiding known life-threatening complications of intravenous IgG therapy.

Acute Kidney Injury↗

Cerebral fat embolism studied with MRI and SPECT.

In a patient with fat embolism to the brain CT showed no abnormality. MRI performed after recovery from coma, when the patient had aphasia and quadriparesis, demonstrated multiple high signal abnormalities in the white matter on both T1- and T2-weighted images. HMPAO-SPECT showed left-sided hypoperfusion which resolved in parallel with clinical improvement 1 month later.

Adult↗

Sympathetic skin response and R-R interval variation in rheumatoid arthritis. Two simple tests for the assessment of autonomic function.

Autonomic nervous system involvement with peripheral neuropathy is a well known complication of rheumatoid arthritis (RA). In the assessment of autonomic function of patients with rheumatoid arthritis, we performed sympathetic skin response (SSR) and R-R interval variation (RRIV) tests in 30 patients and in 30 normal controls. Of 30 patients, 5 had complaints of clinical dysautonomic symptoms. SSRs were abnormal in 6 of 30 patients, whereas 8 showed abnormal RRIVs during deep breathing. Nine of 30 patients also showed electrophysiologic evidence of peripheral neuropathy. All 5 of the patients with clinical dysautonomic symptoms showed abnormal SSR and RRIV test results. No patients with normal results on both tests had clinical dysautonomia. This study showed that there are frequent abnormalities in SSR and RRIV tests in patients with rheumatoid arthritis whether there is a clinical symptom of autonomic dysfunction or not.

Action Potentials↗

Spastic paraparesis associated with portal-systemic venous shunting due to congenital hepatic fibrosis.

We report a case of progressive spastic paraparesis in a 45-year-old man with total portal-systemic shunting, which developed spontaneously due to congenital hepatic fibrosis. Cellular functions of the liver, except for an elevated blood ammonia level, were within normal limits, as is usual in congenital hepatic fibrosis. This case shows that spastic paraparesis following portal-systemic shunting may occur without liver failure.

Ammonia↗

Glomerular lesions induced in the rabbit by physicochemically altered homologous IgG.

Immunization of rabbits with physicochemically altered homologous or even autologous IgG induces formation of antibodies combining with IgG of rabbit and of foreign species. Cardiac but not renal lesions were reported in such animals. This study examined the nephritogenic potential of the immune response to cationized or heat-aggregated homologous IgG of b9 or b4 allotype in rabbits of the b4 allotype. Rabbits injected with either b9 or b4 cationized IgG produced antibodies reactive with rabbit and human IgG and with histones; they also developed abnormal glomerular deposits of IgG b4 and C3 corresponding to alterations of the glomerular basement membranes (GBM). Rabbits injected with either b9 or b4 aggregated IgG developed antibodies reactive with rabbit and human IgG and abnormal glomerular deposits of IgG b4 and C3 in the GBM and in the mesangium with subendothelial and mesangial electron-dense deposits. Some rabbits in both groups had proliferative and exudative glomerulonephritis and proteinuria. The results showed that immunization of rabbits with physicochemically altered homologous IgG induces an immune response to rabbit and human IgG and to histones as well as glomerular deposits of autologous IgG and C3 and other glomerular lesions.

Animals↗