Biomedical subjects

T C Lu

Publications and source records attributed to T C Lu.

At least 19 recordsLinked to original sources

PubMed2001

Evidence for alterations in circulating low-molecular-weight antioxidants and increased lipid peroxidation in smokers on hemodialysis.

BACKGROUND/AIM: Cardiovascular disease is the major cause of mortality in dialysis patients, accounting for about 40% of deaths in most large registries. Oxidative stress has been strongly implicated in the pathogenesis of these events. As end-stage renal disease is a state of elevated free radical activity, the aim of the present study was to investigate the negative impact of smoking in 57 male hemodialysis patients. METHODS: The patients, who were 20-85 years of age (mean age 51.0 +/- 14 years), had been on hemodialysis for at least 6 months before participating in this study. Fasting blood sampling for serum lipid, albumin, urate and lipophilic antioxidants such as tocopherols, carotenes, ascorbate and lipid peroxides was performed. RESULTS: The plasma malondialdehyde (MDA) concentration was significantly higher in hemodialysis patients who smoked compared to hemodialysis patients who were nonsmokers (1.92 +/- 0.52 vs. 1.59 +/- 0.42 nmol/ml, p = 0.006). No association was found between levels of MDA in smokers and parameters such as body mass index, serum cholesterol, serum triglycerides and smoking index. There were no significant differences in the plasma levels of uric acid, alpha-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-carotene, beta-carotene and retinol between the two groups. A significantly lower level of plasma ascorbate was observed in hemodialysis patients who smoked compared to the nonsmoking hemodialysis patients or healthy controls (4.59 +/- 4.0 vs. 9.57 +/- 4.0 and 10.16 +/- 4.6 microg/ml, p < 0.05). Moreover, in smokers, the plasma levels of ascorbate were negatively correlated with the levels of plasma MDA (r = -0.43, p < 0.001) of each patient. Partial correlation analysis of the plasma levels of the measured antioxidants and the smoking index revealed a negative correlation between the plasma levels of lipid-normalized lycopene and the smoking index (r = -0.53, p < 0.05). CONCLUSION: Our data suggest that cigarette smoking further increases plasma-circulating products of lipid peroxidation, which are already increased in nonsmoking hemodialysis patients as compared to matched healthy controls. The lower plasma levels of ascorbate in hemodialysis patients who smoke suggest that these patients may be more susceptible to oxidative tissue damage caused by smoking.

Adult↗

PubMed2001

Renal oncocytoma in acquired renal cystic disease.

Renal oncocytoma is a rare benign tumor of the kidney that accounts for about 5% of renal tumors. Acquired renal cystic disease (ARCD) is commonly seen in dialyzed patients. However, the occurrence of renal oncocytoma in ARCD has rarely been reported. We report such a case in a 67-year-old man who had hypertension-associated end-stage renal disease and had received regular hemodialysis for 5 years. Radiologic diagnostic studies demonstrated a renal mass in the left atrophic cystic kidney that increased in size from 2 cm to 4 cm during 2 years of follow-up. Under the diagnosis of renal cell carcinoma, he received left radical nephrectomy. The pathologic examination revealed renal oncocytoma with a well-cirumscribed, homogenous, mahogany-brown tumor on a background of ARCD. Although patients with ARCD have a higher incidence of renal malignancies, renal oncocytoma may occur in these patients and may be managed conservatively.

Adenoma, Oxyphilic↗

PubMed2000

Isolation of immunoglobulin from egg yolk by anionic polysaccharides.

Isolation conditions of immunoglobulin in egg yolk (IgY) were optimized by the addition of various levels of Na-alginate (Alg), lambda-carrageenan (lambda-Cg), Na-carboxymethyl cellulose (CMC), and pectin (PC) to 6-fold diluted yolk. The mixtures were then reacted at pH 4.0-6.0 for 30 min. The optimal isolation conditions of IgY for Alg, lambda-Cg, and CMC were at the 0.1% level and at pH 5.0, while those for PC were at the 0.15% level and at the same pH. The remaining lipid and remaining protein in the supernatants thus obtained was 0.5-3.8% and 10-17%, respectively, and more than 90% of lipoproteins were precipitated. The IgY recovery was determined to be 33-74% by means of single radial immunodiffusion method when IgY was isolated under the optimal conditions. PC showed the best recovery of IgY, while lambda-Cg provided the least. The interactions between polysaccharides and lipoproteins were mainly ionic bonds, hydrophobic interactions, and hydrogen bonds as determined by the addition (0-2.0 M) of NaSCN or urea to the polysaccharide-lipoprotein precipitates.

Alginates↗

PubMed2000

Lipophilic antioxidants and iron status in ESRD patients on hemodialysis.

Cardiovascular disease remains the major cause of mortality in hemodialysis patients. Abnormal oxidative stress and impaired antioxidant defense may contribute to accelerated atherogenesis associated with uremia. As oxidative modification of lipids appears to be a prerequisite for the development of atherosclerotic lesions, lipophilic antioxidants may be protective. The aim of this study was to determine the plasma levels of lipophilic antioxidants in 82 hemodialysis patients and 30 controls and to investigate the influence of body iron status on the levels of lipophilic antioxidants. The patients were categorized into 3 groups according to their serum ferritin levels. We found that the plasma levels of lycopene, delta-tocopherol, gamma-tocopherol and retinol of hemodialysis patients were lower than those of controls. On the other hand, both absolute and lipid-normalized plasma lycopene levels were significantly reduced in those patients in the groups with higher ferritin levels as compared to those with lower ferritin levels. In addition, our study showed that the lipid-normalized plasma levels of beta-carotene and alpha-carotene of hemodialysis patients with higher ferritin levels were lower than those of the patients with lower levels. These data suggest that the plasma levels of lipophilic antioxidants are altered in end-stage renal disease on hemodialysis and may be considered as markers of oxidative stress in these patients. Most importantly, elevated serum ferritin levels may affect the levels of these lipophilic antioxidants.

Adult↗

PubMed1999

Salmonella infection in total hip replacement--report of successful reimplantation and review of the literature.

A case of Salmonella enteritidis group C infection following total hip replacement was treated by resectional arthroplasty and appropriate antibiotics. Total hip replacement with reimplantation of an antibiotic-impregnated cemented hip prosthesis was performed five months later. The postoperative course was smooth and hip function was good, without any sign of infection recurrence throughout 10 years of follow-up. The treatment protocol and clinical results are discussed along with a review of the literature.

Arthroplasty, Replacement, Hip↗

PubMed1993

Force decay of elastomeric chain--a serial study. Part II.

This study was designed to evaluate the relaxation of elastomeric chain over time. The purposes were to compare the force decay curves of three variously stretched lengths, as well as to compare transparent and grey elastomeric chains. The elastomeric chains were fixed on a stainless steel framework that was submerged in 37 degrees C water bath for 6 weeks. The elastic forces of the chains were measured by a Dial-Type dynamometer, and recorded at the initial activation, first hour, eighth hour, twenty-fourth hour, third day, and then weekly to 6 weeks. The stretched length of the chains were decreased 0.5 mm per week. The results showed: (1) The sequence of stretch force at each time measurement of the Rocky Mountain clear energy chain was 40 mm > 35 mm > 30 mm. However, the percentage of remaining force was 40 mm < 35 mm < 30 mm. (2) The remaining force and the percentage of remaining force of the American Orthodontic short transparent chain were greater than the remaining force of the gray chain. (3) The remaining force and the percentage of remaining force of the Rocky Mountain clear chain with 40 mm stretch were greater than that of the American Orthodontic transparent and grey chains. (4) The effective force for canine retraction (184 gm) can be maintained by the Rocky Mountain energy chain with 40 mm, 35 mm, and 30 mm stretch for about 3 weeks, 1 week, and 3 days, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1991

Bond strength with various etching times on young permanent teeth.

Tensile bond strengths of an orthodontic resin cement were compared for 15-, 30-, 60-, 90-, or 120-second etching times, with a 37% phosphoric acid solution on the enamel surfaces of young permanent teeth. Fifty extracted premolars from 9- to 16-year-old children were used for testing. An orthodontic composite resin was used to bond the bracket directly onto the buccal surface of the enamel. The tensile bond strengths were tested with an Instron machine. Bond failure interfaces between bracket bases and teeth surfaces were examined with a scanning electron microscope and calculated with mapping of energy-dispersive x-ray spectrometry. The results of tensile bond strength for 15-, 30-, 60-, or 90-second etching times were not statistically different. For the 120-second etching time, the decrease was significant. Of the bond failures, 43%-49% occurred between bracket and resin interface, 12% to 24% within the resin itself, 32%-40% between resin and tooth interface, and 0% to 4% contained enamel fragments. There was no statistical difference in percentage of bond failure interface distribution between bracket base and resin, resin and enamel, or the enamel detachment. Cohesive failure within the resin itself at the 120-second etching time was less than at other etching times, with a statistical significance. To achieve good retention, to decrease enamel loss, and to reduce moisture contamination in the clinic, as well as to save chairside time, a 15-second etching time is suggested for teenage orthodontic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Etching, Dental↗

PubMed1986