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S L Lui

Publications and source records attributed to S L Lui.

At least 19 recordsLinked to original sources
PubMed2005

Minimally destructive analysis of aluminum alloys by resonance-enhanced laser-induced plasma spectroscopy.

Aluminum alloys were analyzed for minor components and trace impurities using double pulse resonance-enhanced laser-induced plasma spectroscopy. The first laser pulse at 532 nm ablated the sample. The second laser pulse at 396.15 nm resonantly excited the Al atoms to rekindle the plasma plume. Emissions from Mg, Cu, Si, and Na were observed. At laser energies below the damage threshold, the analyte emissions were already orders of magnitude above the background noise. Nonresonant probes of comparable sensitivity would melt and deform the sample surface. Because of the lower etch rate of resonant probes, depth profiling at nanometer resolution was possible. Using this method, the variation of [Na] with depth was measured for high-purity samples. In contrast, nonresonant probes required 5 times the fluence and proportionally poorer resolution. Worse yet, the associated heating and laser remelting modified the [Na] profile.

Journal Article↗
PubMed2005

Modulation of intra-pulmonary TGF-beta expression by mycophenolate mofetil in lupus prone MRL/lpr mice.

We investigated the expression profile of inflammatory cytokines in the lung of lupus-prone MRL/lpr mice and evaluated the therapeutic potential of mycophenolate mofetil (MMF) in reducing pulmonary cytokines in active lupus. Eight-week old female MRL/lpr mice (n = 20) were treated with MMF in vehicle by oral gavage. Disease control MRL/lpr mice (n = 30) or normal control MRL mice (n = 20) received vehicle alone. The mice were sacrificed after eight or 12 weeks of treatment. Gene expression and protein synthesis of IL-1beta, MCP-1 and TGF-beta1 in lung tissues were determined. We found an increase in the gene expression of IL-1beta, MCP-1 and TGF-beta1 in lung tissues of untreated MRL/lpr mice compared with MRL mice at either 16 weeks or 20 weeks of age. MMF treatment significantly prolonged the survival of MRL/lpr mice, down-regulated the gene expression of IL-1beta, MCP-1 and TGF-beta1 in lung tissues at the end of eight or 12 weeks of treatment. Protein synthesis of TGF-beta1 was decreased following eight weeks of MMF treatment. We conclude that MMF treatment can reduce the TGF-beta1 gene expression and protein synthesis in lung tissues of lupus-prone mice. Our findings provide experimental data suggesting a beneficial potential of MMF therapy in pulmonary involvement of lupus.

Animals↗
PubMed2005

Paradoxical deterioration during anti-tubercular treatment in a dialysis patient on maintenance steroid therapy.

We report a 38-year-old Chinese woman with lupus nephritis on peritoneal dialysis and long-term maintenance steroid therapy. This patient developed paradoxical deterioration during anti-tubercular therapy for tuberculous lymphadenitis. The deterioration resolved spontaneously without change to pharmacotherapy. Paradoxical deterioration that may spontaneously resolve is a potential complication of anti-tubercular treatment in patients on long-term renal replacement therapy.

Adrenal Cortex Hormones↗
PubMed2002

Reactivation of systemic lupus erythematosus in a dialysis patient after tuberculous peritonitis.

The disease activity of patients suffering from lupus nephritis usually becomes quiescent after the onset of end stage renal failure. Reactivation of lupus activity, especially after a long period of dialysis, is uncommon. Factors that might trigger off lupus reactivation after dialysis have not been well defined. We report a case of a 43-year-old Chinese woman on long-term peritoneal dialysis, who developed lupus reactivation with cerebral involvement 2 weeks after she was diagnosed to have tuberculous peritonitis. The close temporal relationship between the tuberculous peritonitis and the lupus reactivation raise the possibility that the tuberculous infection might have triggered off the lupus reactivation.

Adult↗
PubMed2002

Effect of mycophenolate mofetil on severity of nephritis and nitric oxide production in lupus-prone MRL/lpr mice.

Mycophenolate mofetil (MMF), an immunosuppressive drug commonly used in organ transplantation, is increasingly being used to treat autoimmune diseases including systemic lupus erythematosus (SLE). Excessive production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of lupus nephritis. We evaluated the effect of MMF on the severity of nephritis and the production of NO in lupus-prone MRL/lpr mice. Eight-week-old female MRL/lpr mice (n = 20) were treated with MMF (100 mg/kg/day) by oral gavage for 12 weeks. Control mice (n = 20) received vehicle on the same schedule. The mice were killed after 12 weeks of treatment. Treatment with MMF significantly decreased the amount of proteinuria, prolonged survival and reduced the histological severity of glomerulonephritis. Urinary nitrite/nitrate excretion in the MMF-treated mice was significantly reduced during the first 8 weeks of treatment. However, by the end of the 12 weeks' treatment period, there was no significant difference between vehicle and MMF-treated mice in terms of urinary nitrite/nitrate excretion, intra-renal production of NO, expression of iNOS protein and induction of iNOS mRNA. We conclude that MMF is effective in attenuating the severity of nephritis in MRL/lpr mice. The beneficial effects of MMF on lupus nephritis during the early phase of the disease might be partly attributed to the inhibition of NO production. The inhibitory effect of MMF on NO production diminishes as the disease progresses. MMF probably has additional, as yet undefined mode of actions to fully account for its beneficial effects on lupus nephritis.

Animals↗
PubMed2001

Nosocomial outbreak of parvovirus B19 infection in a renal transplant unit.

BACKGROUND: Parvovirus B19 (B19) infection is known to cause chronic infection leading to anemia in immunocompromised patients. Although nosocomial B19 infections in immunocompetent patients have been documented, no outbreaks in immunocompromised patients have been previously reported. Whether transmission can occur from a patient with chronic infection is also unknown. METHODS: An outbreak of B19 infection in a renal transplant unit was investigated by molecular analysis of the virus strains and a case-control study. RESULTS: Three patients had genetically identical virus strains suggesting the occurrence of nosocomial transmission. The index case transmitted infection many weeks after the onset of her clinical symptoms. Other patients at risk of acquiring infection were those most intensively immunosuppressed. Viral load in the serum correlated with the hematological response. A rebound in the viral load was associated with clinical relapse and the failure of i.v. immunoglobulin therapy. CONCLUSION: Nosocomial transmission of B19 can occur from immunocompromised patients even when they are in the chronic stage of the infection. The clinical and virological response to i.v. immunoglobulin therapy is variable and depends on the overall level of immunosuppression of the patient.

Adult↗
PubMed2001

Tuberculosis infection in Chinese patients undergoing continuous ambulatory peritoneal dialysis.

A retrospective study of the prevalence and pattern of tuberculosis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) was performed. Thirty-eight cases of tuberculosis were diagnosed among 790 patients (18 men, 20 women; mean age, 58 +/- 12.6 years) between July 1994 and June 2000. The interval between the initiation of CAPD and onset of tuberculosis ranged from 1 to 168 months (median, 22 months). There were 18 cases of pulmonary tuberculosis, 14 cases of tuberculous peritonitis, 5 cases of tuberculous lymphadenitis, and 1 case of tuberculous synovitis. Patients with pulmonary tuberculosis usually presented with fever, constitutional symptoms, and pleural effusion or pulmonary infiltrates on chest radiograph. Abdominal pain and turbid dialysate were the main presenting symptoms in patients with tuberculous peritonitis. Diagnosis was established by positive culture in 20 patients, typical histological characteristics on a tissue biopsy specimen in 10 patients, and response to empirical antituberculous treatment in 8 patients. The duration of symptoms before the diagnosis of tuberculosis and initiation of antituberculous treatment ranged from 7 to 57 days (median, 30 days). Antituberculous treatment consisted of isoniazid, rifampicin, pyrazinamide, and ofloxacin for 9 to 15 months. Antituberculous treatment generally was well tolerated. Twenty-seven patients (71%) completed antituberculous treatment. No recurrence of tuberculosis was observed after a mean follow-up of 19.8 months. Eleven patients (29%) died while on antituberculous treatment; none of the deaths appeared to be directly caused by tuberculosis. We conclude that: (1) tuberculosis is prevalent among CAPD patients in our locality; (2) extrapulmonary tuberculosis, particularly tuberculous peritonitis, is common; and (3) a high index of suspicion for tuberculosis among CAPD patients is warranted to ensure early diagnosis and prompt initiation of treatment.

Aged↗
PubMed2001

Effect of mycophenolate mofetil on nitric oxide production and inducible nitric oxide synthase gene expression during renal ischaemia-reperfusion injury.

BACKGROUND: Recent animal data suggest that inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) plays an important role in the pathogenesis of renal ischaemia-reperfusion injury (IRI) and that inhibition of iNOS ameliorates IRI. Mycophenolate mofetil (MMF), a lymphocyte selective anti-proliferative agent, has been shown to inhibit NO production in vitro. The aim of this study is to evaluate the effect of MMF on NO production and iNOS gene expression in vivo during renal IRI. METHODS: Renal IRI was induced by clamping the left renal pedicle of male BALB/c mice for 30 min, followed by 15 min of reperfusion. The mice received placebo or MMF at 40, 80 or 120 mg/kg/day by oral gavage for 5 days before the operation. Sham-operated mice served as the operation control. The amount of NO produced and the level of iNOS gene expression in the kidney tissue during IRI was assessed by spin trapping electron paramagnetic resonance (EPR) spectroscopy and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) respectively. RESULTS: In the sham-operated kidneys, only low levels of NO and iNOS mRNA were detected. In mice with renal IRI, the amount of NO detected was significantly increased, which was reduced in a dose dependent fashion by pre-treatment with MMF. Pre-treatment with MMF also substantially reduced iNOS gene expression in the kidney tissue. CONCLUSIONS: We conclude that pre-treatment with MMF inhibits the production of NO and the induction of iNOS gene expression in the kidney during IRI. These results suggest that MMF might have the potential to ameliorate renal IRI.

Animals↗
PubMed2001

Progressive demyelinating neuropathy after initiation of continuous ambulatory peritoneal dialysis--report of two cases.

We report on two patients who developed rapidly progressive demyelinating neuropathy within 6 to 10 weeks after the initiation of continuous ambulatory peritoneal dialysis. The neuropathy in one patient resolved after kidney transplantation while that of the other patient improved with immunosuppressive therapy. The close temporal relationship between the initiation of peritoneal dialysis and the onset of neuropathy suggests that these two events may be causally related.

Adult↗
PubMed2001

A retrospective survey of attitudes toward acceptance of peritoneal dialysis in Chinese end-stage renal failure patients in Hong Kong--from a cultural point of view.

OBJECTIVE: We undertook to study the attitudes toward dialysis of patients approaching end-stage renal failure and to analyze those attitudes from a cultural perspective. SETTING: The study was performed in the pre-dialysis clinic of a tertiary referral renal center. PATIENTS: All patients of Chinese ethnic origin seen in the pre-dialysis clinic from 1995 to 2000 for assessment of dialysis therapy were included. METHOD: We performed a retrospective analysis of patient records with regard to attitudes of the patients toward dialysis, reasons for those attitudes, and factors that could lead to a subsequent change in attitude. RESULTS: We assessed 462 patients over the 6-year period. Their mean age was 65.5 +/- 13.3 years, and 43.9% of the patients had diabetes. Peritoneal dialysis (PD) was offered to 74% of the patients, and hemodialysis (HD) to 3.9%. Among the patients offered PD, only 44% accepted dialysis. After counselling, 54% of the patients who originally declined PD ultimately accepted it. The major reasons for refusing PD were the ideas of "having lived long enough" and "lack of family support." Most other reasons could be overcome by counselling. Only a minority of patients demanded hemodialysis. CONCLUSIONS: Declining an offer of dialysis was common. Counselling helped patients to accept PD. Certain cultural elements that hindered acceptance of dialysis were involved in the ideas of "having lived long enough" and "lack of family support." Those cultural elements should be tackled more specifically during counselling.

Adult↗
PubMed2000

Simultaneous removal and reinsertion of Tenckhoff catheters for the treatment of refractory exit-site infection.

Exit-site infection (ESI) refractory to medical therapy is an important complication of continuous ambulatory peritoneal dialysis (CAPD). Between July 1994 and June 1998, 28 patients in our hospital underwent simultaneous removal and reinsertion of Tenckhoff catheters for the treatment of refractory ESI. The ESI was caused by Pseudomonas aeruginosa in 22 patients (78%), methicillin-resistant Staphylococcus aureus in 5 patients (18%), and diphtheroid bacilli in 1 patient (4%). The patients had received antibiotic treatment for a mean duration of 11.6 +/- 5.8 weeks (range: 3-28 weeks) before their operations. During each operation, the old Tenckhoff catheter was removed and a new catheter was inserted in the opposite side of the abdomen. CAPD was resumed after two weeks of intermittent peritoneal dialysis. All patients received intravenous antibiotic cover for seven days after the operation. Early post-operative complications were uncommon. At one year after the operation, 22 patients (78%) were free of ESI. Six patients (22%) had a recurrence of ESI 21.3 +/- 6 weeks (range: 16-32 weeks) after their operation. All new infections were treated successfully with antibiotics. Seven patients (25%) had one episode of peritonitis each, all of which resolved with intraperitoneal antibiotic treatment. We conclude that simultaneous removal and reinsertion of Tenckhoff catheters is a safe and effective method for the treatment of refractory ESI. The procedure alleviates the need for temporary hemodialysis and allows an early return to CAPD.

Adult↗