Biomedical subjects

C J Yen

Publications and source records attributed to C J Yen.

24 records · Page 2Linked to original sources

PubMed1995

Continuous ambulatory peritoneal dialysis in the elderly: a seven-year experience.

This is a retrospective comparison of the status among the elderly (> or = 60 years, 23 patients) and younger patients (< 60 years, 31 cases) who initiated continuous ambulatory peritoneal dialysis (CAPD) between January 1986 and December 1992 at the National Taiwan University Hospital. The distribution of underlying renal diseases differed in the two groups with diabetes (56%) as the most common disease in the elderly, in contrast to glomerulonephritis (60%) in the younger patients. Haemodialysis intolerance and patient preference were the main reasons leading to the use of CAPD in both groups. Social rehabilitation status was poorer in the elderly group. The difference in cumulative risk of the first peritonitis episode and the technique failure rate were not statistically significant. The major causes of mortality were of vascular origin in both groups. In conclusion, similarities in the technique failure rate and the cumulative risk of peritonitis imply that CAPD is an acceptable alternative long-term dialysis therapy for geriatric patients.

Adult↗

PubMed1995

Disintegrin modulates rat glomerular mesangial cell behavior.

Disintegrins are a group of molecules containing Arg-Gly-Asp (RGD) sequence which can interfere with cell-matrix interaction. Rat mesangial cells are known to express an RGD-sensitive integrin receptor. We investigate the effect of a potent disintegrin, triflavin, on rat mesangial cell adhesion and proliferation. While synthetic RGD-containing peptide (GRGDS) inhibits mesangial cell adhesion to fibronectin, type I and type III collagen, triflavin has a similar but much more potent effect. Triflavin, when added to the medium, inhibits serum-stimulated rat mesangial cell proliferation in both growing and growth-arrested cells. In serum-free medium, platelet-derived growth factor promoted mesangial cell growth is also inhibited by triflavin. When coated as a substratum, both GRGDS and triflavin inhibit mesangial cell growth. The inhibition of proliferation by exogenously added triflavin and GRGDS is, at least in part, due to their antiadhesive effect. We conclude that triflavin can modulate both adhesion and proliferation of rat mesangial cells.

Amino Acid Sequence↗

PubMed1995

Effect of intraperitoneally administered agents on human peritoneal mesothelial cell growth.

During continuous ambulatory peritoneal dialysis, the peritoneal mesothelial cell layer is under continuous sloughing and regeneration processes. Agents unfavorable for mesothelial cell growth may be harmful to the peritoneal membrane. We investigated whether frequent intraperitoneally instilled agents affect mesothelial cell growth. Peritoneal mesothelial cells were cultured from the human omentum. The proliferation was assessed by using a modified methyltetrazolium assay and confirmed by Coulter cell counting. The results showed that a high-glucose medium and heparin inhibited mesothelial cell growth. Cephalothin at the usual intraperitoneal loading and maintenance doses is toxic to mesothelial cells. Ceftazidime is toxic to mesothelial cells at its loading dose and inhibits growth at its maintenance dose. Aminoglycosides including netilmicin, gentamicin, and amikacin all had inhibitory effects at the loading and maintenance dose ranges. Vancomycin had no effect. The usual combinations of heparin and cephalothin with netilmicin or gentamicin as the initial treatment regimen for bacterial peritonitis are toxic to mesothelial cells. These results suggest that some intraperitoneal agents potentially may hamper mesothelial cell regeneration. The judicious use of heparin and the proper choice of antibiotic combinations may be warranted from the point of view of peritoneal protection.

Anti-Bacterial Agents↗

PubMed1995

Infection associated with double lumen catheterization for temporary haemodialysis: experience of 168 cases.

A total of 227 patients with renal failure requiring acute haemodialysis with placement of a total of 260 Medcorp double lumen catheters at National Taiwan University Hospital from July 1992 to July 1993 were reviewed. Among them, only 135 patients receiving a total of 168 catheter placements and a complete infectious work-up were selected for this study. The mean age of the patients was 55 years (range 15-89 years); 63 (46.7%) were male and 75 (53.3%) were female. The three major reasons for dialysis were chronic glomerular disease (CGN; 49%), diabetic nephropathy (13%) and nephritis associated with systemic lupus erythematosus (SLE; 11%). The catheters remained in place for an average of 27.8 days (9-73 days) and each catheter was used for an average of eight treatments (2-26). The reasons for catheter removal were classified as: availability of permanent vascular access (48%), recovery of renal function (10%), scheduled duration (30 days, not every case; 4%), expiration of patient (10%), suspicion of catheter-related infections (15%), and catheter thrombosis/occlusion (9%). Seven cases with local haematoma and one case of pneumothorax were also identified (total 5%). In total, a 21.4% catheter-related infection rate was observed and micro-organisms such as Staphylococcus aureus (33%), coagulase-negative staphylococci (36%) and Enterococcus (19%) were isolated. The cumulative probability of patients remaining free from catheter-related infections was about 75% by the end of the fourth week post-catheter insertion, and decreased to less than 50% near the end of the second month of persistent catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Age-associated changes in interferon-gamma and interleukin-4 secretion by purified human CD4+ and CD8+ T cells.

Aging is associated with a decline in immune function. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), two important immune deviation-related cytokines, are mainly produced by type 1 and type 2 T cells, respectively. To investigate the age-associated changes in the secretion of these two cytokines, 20 elderly and 20 young subjects fulfilling the SENIEUR protocol were enrolled. The ratios of CD4+ to CD8+ T cells were not different between the two age groups. The CD4+ and CD8+ T cells were purified by a magnetic cell sorting system, and then activated by concurrent anti-CD3 and anti-CD28 stimulation. The released cytokines were determined by ELISA. Both the CD4+ and the CD8+ T cells of the elderly individuals secreted a significantly larger amount of IFN-gamma after activation. Profound IL-4 production by CD8+ T cells was observed in the older subjects compared with that of the young subjects. These data suggested that age-associated decrease in immunity may be related to an imbalance in the secretion of immune deviation cytokines. The number of IL-4-secreting CD8+ T cells (T cytotoxic 2) rose significantly in the older individuals. Our design also provided a useful way to differentiate the T cell subsets secreting the same cytokine, such as IFN-gamma-producing T helper 1 and T cytotoxic 1 cells.

Adolescent↗

PubMedDate not supplied

Systemic lupus erythematosus and peritoneal dialysis: outcomes and infectious complications.

OBJECTIVE: Systemic lupus erythematosus (SLE) is the most common secondary glomerulonephritis resulting in end-stage renal disease (ESRD) among young adults in Taiwan. Studies of the infectious complications and outcomes among such SLE patients undergoing peritoneal dialysis (PD) are limited. DESIGN: A retrospective age- and gender-matched case control study. SETTING: A university teaching hospital. PATIENTS: There were 23 SLE patients with ESRD receiving PD for more than 3 months during the past 15 years. Another 46 age- and gender-matched non-SLE nondiabetic patients receiving PD were selected as the control group in this study. INTERVENTION: All patients underwent PD as renal replacement therapy and were regularly followed up at this hospital. MAIN OUTCOME MEASURES: Technique survival and incidences of exit-site infection (ESI) and peritonitis in these patients. RESULTS: The SLE patients had a lower predialysis serum albumin than the control group (3.16 +/- 0.50 g/dL vs 3.52 +/- 0.50 g/dL, p < 0.01). The incidences of exit-site infection (ESI) and peritonitis were higher for SLE patients than for control patients (p < 0.01 and p < 0.001, respectively). Kaplan-Meier survival analysis indicated that SLE patients had shorter time intervals to first infectious complications, and poorer technique survival. Infection was the major cause of dropout and mortality in the SLE patients. The SLE patients had a reduced chance of receiving a renal transplant. The use of steroids by SLE patients was associated with a higher incidence of peritonitis (p = 0.04), but association with ESI was insignificant. In a Cox regression model, the underlying SLE was the only risk factor for technique failure and time interval to first infectious complication. CONCLUSION: SLE patients undergoing PD are more susceptible to infection than age- and gender-matched non-SLE nondiabetic patients and have poorer technique survival. Systemic lupus erythematosus itself may further compromise the immunity of uremic patients.

Adult↗