On the Paramagnetic-Like Susceptibility Peaks at Zero Magnetic Field in [Formula: see text] Single Crystals

A weakly temperature-dependent paramagnetic-like susceptibility peak at zero magnetic field is observed in [Formula: see text] with only marginal amount of ferromagnetic impurities. The ferromagnetic hysteresis loop and the magnetic moment splitting between zero-field-cooled and field-cooled processes indicate ferromagnetism in the samples. The paramagnetic-like susceptibility peak height is proportional to the remanent magnetic moment of hysteresis loops. High-resolution transmission electron microscope image supports that the observed ferromagnetic feature originates from lattice distortion. These results imply that the weakly temperature-dependent paramagnetic-like susceptibility peak originates from weak lattice distortion and/or superparamagnetism.

Chronic fatigue in long-term peritoneal dialysis patients

OBJECTIVE

Fatigue is a common symptom in long-term dialysis patients. This study investigated possible clinical factors which may cause the development of fatigue in patients receiving peritoneal dialysis (PD). We also investigated the relationship between total solute clearance (TSC) and fatigue symptoms in PD patients.

DESIGN

A cross-sectional study design was used to compare the clinical characteristics among groups of PD patients classified by different degrees of fatigue. The relationship among dialysis adequacy (including Kt/V(urea) and weekly creatinine clearance; C(cr)), clinical characteristics and fatigue symptoms were also assessed.

SETTING

The PD unit of a major university teaching hospital in Taipei, Taiwan.

PATIENTS

Consecutive patients who had received PD for a minimum duration of 4 months were recruited for participation in the study. Patients were excluded if they had a history of ischemic heart disease, severe heart failure (NYHA function III or IV), malignant neoplasm, active infection, major psychiatric problems, chronic obstructive pulmonary disease, or disturbed consciousness. Finally, a total of 64 patients, 31 of whom were receiving continuous ambulatory peritoneal dialysis and 33 who were receiving continuous cycling-assisted peritoneal dialysis, were enrolled in the study.

METHODS

Fatigue was evaluated using a specially designed questionnaire that includes fourteen items. Patients were divided into three groups according to their fatigue scores (FS): mild (FS, 0-3), moderate (FS, 4-8), and severe (FS, 9-14) fatigue. The demographic data, dialysis variables, and clinical parameters of patients were compared among these groups. The relationship between fatigue and TSC was also examined.

RESULTS

The FS were correlated with serum intact parathyroid hormone (iPTH) level and total cholesterol concentration (p < 0.05). A linear correlation was also noted between serum iPTH level and total cholesterol level. When the patients were divided into an adequate- and an inadequate-dialysis group according to values of TSC, Kt/V(urea) as well as weekly creatinine clearance, a significant correlation was found between weekly C(cr) and FS.

CONCLUSION

This study has demonstrated that dialysis adequacy plays a key role in the development chronic fatigue. In addition, weekly C(cr) was better correlated with fatigue than Kt/V(urea).

Dipyridamole inhibits TGF-beta-induced collagen gene expression in human peritoneal mesothelial cells

BACKGROUND

Peritoneal matrix accumulation is characteristic of peritoneal fibrosis (PF). Continuous ambulatory peritoneal dialysis (CAPD) patients who had persistent transforming growth factor-beta (TGF-beta) in their drained effluent had an increased risk of PF. We previously reported that TGF-beta stimulates the expression of types I and III collagen mRNA in cultured human peritoneal mesangial cells (HPMCs), which may predispose them to develop PF. Pharmacological interventions to attenuate TGF-beta-stimulated matrix accumulation in HPMC may have therapeutic potential for the treatment of PF. The SMAD family and the extracellular signal-regulated protein kinase (ERK1/2, p44/p42) pathways have been shown to participate in TGF-beta signaling. Our current study identified these signal pathways in HPMCs and investigated the molecular mechanisms involved in the inhibitory effects of dipyridamole on TGF-beta-induced collagen gene expression in HPMCs.

METHODS

HPMCs were cultured from human omentum by an enzyme digestion

METHOD

Expression of collagen alpha1(I) mRNA was determined by Northern blotting. The SMAD proteins and the ERK1/2 activity were determined by Western blotting.

RESULTS

TGF-beta-stimulated collagen alpha1(I) mRNA expression of HPMC was inhibited by dipyridamole in a dose-dependent manner. Smad2 and ERK1/2 were activated in response to TGF-beta; however, TGF-beta had little effect on the protein expression of Smad4. The addition of PD98059, which blocked activation of ERK1/2, suppressed TGF-beta-induced collagen alpha1(I) mRNA expression in a dose-dependent manner. At a concentration that inhibited collagen gene expression (17 microg/mL), dipyridamole suppressed ERK1/2 activation by TGF-beta. In contrast, the same concentration of dipyridamole had no effect on TGF-beta-induced activation of Smad2.

CONCLUSION

Dipyridamole inhibits TGF-beta-induced collagen gene expression in HPMC through modulation of the ERK pathway. Our study of dipyridamole may provide therapeutic basis for clinical applications in the prevention of PF.

Dipyridamole inhibits PDGF-stimulated human peritoneal mesothelial cell proliferation

BACKGROUND

It has been proposed that proliferation of human peritoneal mesothelial cells (HPMCs) accompanied by collagen synthesis may contribute to the development of peritoneal fibrosis (PF) in patients of long-term continuous ambulatory peritoneal dialysis (CAPD). However, the precise molecular mechanism regulating HPMC proliferation has never been reported. Dipyridamole has been reported to have potential as an antiproliferative and antifibrotic agent. We investigated the mechanism and effect of dipyridamole in regulation of HPMC proliferation.

METHODS

HPMCs were cultured from human omentum by an enzyme digestion

METHOD

Cell proliferation was measured by the methyltetrazolium assay and intracellular cAMP was measured using an enzyme immunoassay kit. Cell-cycle distribution of HPMC was analyzed by flow cytometry. Extracellular signal-regulated protein kinase (p44/p42 ERK) activity and expressions of cell-cycle proteins (cyclin D(1), CDK4, pRB and p27(Kip1)) were determined by Western blotting.

RESULTS

The addition of DP suppressed PDGF-stimulated HPMC proliferation by cell-cycle arrest at the G1 phase. The antimitogenic effect of dipyridamole was mediated through the cAMP pathway. PDGF (25 ng/mL) increased the ERK1/2 activity of HPMC within 15 minutes, which maximized at 30 minutes, and the pretreatment with dipyridamole (17 microg/mL) substantially reduced the ERK response to PDGF by approximately 78.5%. PDGF induced elevated protein levels of cyclin D(1), but the CDK4 protein level did not change. Dipyridamole and DBcAMP had no effect on the levels of cyclin D(1) and CDK4 in PDGF-stimulated HPMC. PDGF decreased p27(Kip1) and induced pRB phosphorylation of HPMC. In contrast, dipyridamole prevented PDGF-induced p27(Kip1) degradation and attenuated PDGF-stimulated pRB phosphorylation.

CONCLUSION

Dipyridamole appears to inhibit PDGF-stimulated HPMC proliferation through attenuated ERK activity, preservation of p27(Kip1), and decreased pRB phosphorylation. Thus, dipyridamole may have therapeutic efficacy to prevent or alleviate PF.

Dipyridamole inhibits human peritoneal mesothelial cell proliferation in vitro and attenuates rat peritoneal fibrosis in vivo

BACKGROUND

Peritoneal fibrosis (PF) is one of the most serious complications after long-term continuous ambulatory peritoneal dialysis (CAPD). Proliferation of human peritoneal mesothelial cells (HPMC) and matrix over-production are regarded as the main processes predisposing to PF. Dipyridamole (DP) has been reported to have potential as an antiproliferative and antifibrotic agent. We thus investigated the effect of DP in inhibiting proliferation and collagen synthesis of HPMC. A rat model of peritonitis-induced PF was also established to demonstrate the in vivo preventive effect of DP.

METHODS

HPMC was cultured from human omentum by an enzyme digestion

METHOD

Cell proliferation was measured by the methyltetrazolium assay. Intracellular cAMP was measured using an enzyme immunoassay (EIA) kit. Total collagen synthesis was measured by (3)H-proline incorporation assay. Expression of collagen alpha1 (I) and collagen alpha 1 (III) mRNAs was determined by Northern blotting. The rat model of peritonitis-induced PF was developed by adding dextran microbeads (Cytodex, 8 mg/1 mL volume) to a standardized suspension (3 x 10(9)) of Staphylococcus aureus. DP was administrated via intravenous infusion (4 mg in 1 h) daily for seven days. Macroscopic grading of intraperitoneal adhesions and histological analyses of peritoneal thickness and collagen expression were performed.

RESULTS

Addition of DP to HPMC cultures suppressed serum-stimulated cell proliferation and collagen synthesis. The antimitogenic and antifibrotic effects of DP appear to be predominantly mediated through the cAMP pathway, as DP increased intracellular cAMP in a dose-dependent manner. The macroscopic grade of intraperitoneal adhesion and peritoneal thickness were both significantly increased in animals treated with Cytodex plus S. aureus; on the other hand, DP attenuated these fibrotic changes with statistical significance (P < 0.01). Analysis of gene expression of collagen alpha 1 (I) and alpha1 (III) in the peritoneal tissue of experimental animals yielded similar results.

CONCLUSIONS

This study suggests that dipyridamole may have therapeutic potential in treating peritoneal fibrosis.

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.

Comparison of infectious complications in peritoneal dialysis patients using either a twin-bag system or automated peritoneal dialysis

BACKGROUND

Automated peritoneal dialysis (APD) and twin-bag (TB) systems are two major peritoneal dialysis (PD) modalities. Published data comparing the infectious complications of these modalities is limited. Subjects and methods. Ninety-five patients using APD (the APD group) and 117 patients using TB system (the TB group) were recruited. Among them, 35 patients used both modalities. The two groups' clinical characteristics, incidences of infectious complications, and the time intervals to first PD-related infection were compared.

RESULTS

Clinical characteristics, incidence of exit-site infection (ESI), and time intervals to first ESI were similar in the TB and APD groups. The incidence of peritonitis in the APD group (1.22 episodes/100 patient-months) was significantly (P < 0.001) lower than that of the TB group (2.28 episodes/100 patient-months). Using the Cox proportional hazard model, APD was found to have a lower risk of peritonitis relative to TB systems, with marginal significance (RR 0.58, P = 0.051).

CONCLUSION

APD was found to have a lower peritonitis rate than the TB system. Since reducing the peritonitis rate helps to maintain technical survival during PD, from this viewpoint, APD may be preferred for patients undergoing PD, unless contraindicated.

Trace Metals' abnormalities in hemodialysis patients: relationship with medications

A multicenter collaborative study was performed to investigate the prevalence of abnormal blood contents of 6 trace metals, copper (Cu), zinc (Zn), aluminum (Al), lead (Pb), cadmium (Cd), and mercury (Hg), in hemodialysis (HD) patients and to analyze their relationship with the medications, such as CaCO3, Ca acetate, Al containing phosphate-binding agents, 1,25-dihydroxy vitD3, 1-hydroxy vitD3, and erythropoietin (EPO), as well as hematocrit level, by chi-square statistics. From 6 medical centers in Taiwan, we included 456 patients in maintenance HD for more than 4 months for this study, and they had continued the previously mentioned medications for at least 3 months. Blood samples were collected before initiating HD, and atomic absorption spectrophotometry was used to measure plasma levels of Cu, Zn, and Al as well as whole blood levels of Pb, Cd, and Hg. Three hundred seventy-five (78%) of the HD patients had low plasma Zn levels, that is, <800 microg/L, and the mean (+/-SD) concentration was 705.8 (+/-128.23) microg/L in all subjects. One hundred forty-one (31%) of the HD patients had high plasma Al, that is, >50 microg/L, and the mean (+/-SD) was 44.30 (+/-28.28) microg/L in all subjects. Three hundred thirty-three (73%) of the dialysis patients had high Cd levels, that is, >2.5 microg/L, and the mean (+/-SD) was 3.32 (+/-1.49) microg/L in all subjects. The majority of HD patients had normal blood levels of Cu, PB, and Hg. Only 21 (4. 6%), 5 (1.1%), and 3 (0.06%) patients had elevated blood levels of Cu, Pb, and Hg, respectively. Their mean (+/-SD) blood concentration of Cu, Pb, and Hg were 1,049.78 (+/-233.25) microg/L, 7.45 (+/-3.95) microg/dL, and 3.17 (+/-25.56) microg/L, respectively. Three patients had elevated plasma Hg concentrations, that is, 546, 12.6, and 24.0 microg/L, respectively. In the 152 normal healthy age and sex matched control group, the blood levels of Al, Cd, and Pb were all significantly lower than the HD patients. However, the levels of Cu and Zn were higher in the control group. The Hg level was not significantly different in both groups. There was no statistical difference between patients with normal and abnormal blood levels of trace metals in various medications except Al containing phosphate binder. The Al containing phosphate binder users had significantly higher plasma Al levels (54.71 +/- 26.70 versus 41.15 +/- 28.03 microg/L, p < 0.001) and hematocrit levels (29.61 +/- 4.61 versus 27. 81 +/- 3.91, p < 0.0005). There was no statistical correlation between erythropoietin (EPO) dose and hematocrit level in these patients. In conclusion, the blood level of trace metals of these HD patients except Al was not related to their medications. However, caution must be exercised in interpreting this result as dose and duration of medication; efficiency of HD and water treatment may play an important role. Otherwise, environmental factors, diet, and the aging process may contribute to the trace metal burden in uremia. Thus, Zn and Cu are abundant in seafood, and Cd is abundant in contaminated plants such as rice.

Viral hepatitis infection should be considered for evaluating uremic pruritus in continuous ambulatory peritoneal dialysis patients

Determining the possible association of viral hepatitis infection and degree of pruritus is the primary concern of this study. Ninety-six adequately dialyzed CAPD patients (47 male and 49 female) and 526 normal controls (266 male and 260 female) were enrolled. Blood hemoglobin, ferritin, electrolytes, calcium, phosphate, albumin, urea, creatinine, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase, and bilirubin were analyzed by routine methods. Serum HBsAg was examined, using a radioimmunoassay method and the anti-HCV, an enzyme immunoassay method. All cases were interviewed with a standardized questionnaire. The highest possible pruritus score (PS) was 22. The prevalences of HBsAg(+) and anti-HCV(+) were 14.6% and 17.7%, respectively. The mean PS in all 96 CAPD patients was 11.6 (range 7-22). The mean PS were 11.8 +/- 0.6 and 12.5 +/- 1.0 for patients infected with HBV and HCV, respectively. Both were significantly higher than that (10 +/- 0.9) of patients without hepatitis infection. AST and ALT were significantly higher in patients infected with viral hepatitis than those without. The other biochemical parameters were not significant. Thirty-seven (38.5%) of our 96 patients had mild pruritus (PS < or = 7) and 11 (15.9%) had severe pruritus (PS > or = 15). Of the 83.9% (26/31) patients with viral hepatitis, the grades of skin itching were moderate to severe; whereas those of the patients without viral hepatitis, 53.6% (37/69) belonged to the group of moderate to severe pruritus (p = 0.003, chi 2 test with Yates' correction). The authors recommended screening of viral hepatitis infection to be undertaken for uremic patients with unexplained skin itching.

Incidence of exit-site infection with various exchange systems in continuous ambulatory peritoneal dialysis

BACKGROUND AND PURPOSE

The disconnect twin-bag (TB) system was first introduced in Taiwan for use as an exchange system in continuous ambulatory peritoneal dialysis (CAPD) in 1995. Following its introduction, the incidence of CAPD-associated peritonitis declined, but the incidence of exit-site infection (ESI) increased. To determine the cause of the increase in ESI incidence after the introduction of the TB system, this study compared the incidence of ESI among patients using the O set, ultraviolet antiseptic (UV) device, and the TB system.

METHODS

A total of 170 patients who had received CAPD for more than 3 months were enrolled in this study. Poisson test and Kaplan-Meier survival analysis were used to compare the ESI incidence and ESI-free catheter survival among patients using the O set, UV device, or TB system. Cox stepwise forward proportional hazard analysis was used to assess the impact of sex, education, cause of uremia, age, and type of exchange system on ESI.

RESULTS

The incidences of ESI differed significantly among patients using the three exchange systems, with 20.9, 13.8, and 4.0 episodes per 100 patient-years for patients using the TB system, O set, and UV device, respectively. New patients using the TB system also had a shorter mean interval of ESI-free catheter survival than those using the UV device (26.9 vs 58.8 months, p = 0.002). In the Cox stepwise forward proportional hazard analysis, non-lupus patients had a lower risk of developing ESI than lupus patients (relative risk [RR] 0.40, p = 0.03). The RR of ESI in patients using the UV device was also lower than in those using the TB system (RR 0.15, p < 0.01).

CONCLUSION

In this study, use of the TB system was associated with a higher incidence of ESI. The increased ESI incidence may be related to the heavier mini-transfer set of the TB system. Therefore, special attention should be given to fastening the mini-transfer set tightly during the exchanging procedure to prevent traction on the exit-site, which is associated with an increased incidence of subsequent ESI.

Relationship between dialysis adequacy and quality of life in long-term peritoneal dialysis patients

OBJECTIVE

The purpose of this study was to compare quality of life (QOL) between peritoneal dialysis (PD) patients with adequate and inadequate total solute clearance (TSC). We also tried to determine the relationship between QOL and TSC.

DESIGN

A cross-sectional study design was used in which QOL was evaluated and compared between PD patients with adequate and inadequate TSC.

SETTING

The PD unit of a university teaching hospital.

PATIENTS

Sixty-seven patients were recruited, 38 on continuous ambulatory PD and 29 on continuous cyclerassisted PD.

METHODS

Patients were divided into adequate and inadequate groups, based on the results of either total urea clearance (Kt/Vurea) or total creatinine clearance (weekly CCr). The demographic data, dialysis variables, and clinical parameters of these patients were all collected. QOL was evaluated using the SF-36 questionnaire, which contains eight domains and is a comprehensive and validated instrument for QOL evaluation. QOL of patients in adequate and inadequate groups was compared. The relationship between QOL and TSC was also examined.

RESULTS

Among patients grouped by Kt/Vurea, patients in the adequate group had significantly higher scores in two domains of the SF-36, that is, physical and emotional role functioning, than did those in the inadequate group. The total SF-36 scores were positively correlated with Kt/Vurea when all patients were pooled together. However, among patients grouped by weekly CCr, there was no significant difference in any of the eight domains of the SF-36 between patients in the adequate and inadequate groups. No correlation was found between the total SF-36 scores and weekly CCr.

CONCLUSION

Our study had two important findings: First, PD patients with adequate total solute clearance, based on Kt/Vurea and not on weekly CCr, had a better QOL. Second, Kt/Vurea is better correlated with QOL than weekly CCr. These findings suggest that Kt/Vurea is a better parameter for the clinical evaluation of total solute clearance from the viewpoint of QOL.

Clinical features of and risk factors for fungal peritonitis in peritoneal dialysis patients

BACKGROUND AND PURPOSE

Fungal peritonitis (FP) is a serious complication for peritoneal dialysis (PD) patients and can result in technical failure and mortality. Catheter removal remains the mainstay of treatment. This study sought to identify the risk factors for FP in order to facilitate the prevention of this catastrophic complication.

METHODS

A total of 246 patients who received long-term PD from 1985 to 1998 were included in this retrospective study. Twenty episodes of FP occurred in 19 patients. The clinical characteristics, pathogens, treatment modalities, and outcomes of the FP episodes were retrospectively reviewed. The FP incidence in various demographic and clinical groups, classified according to sex, age, education, and underlying cause of uremia, were compared with the Poisson test.

RESULTS

Thirteen episodes of FP were caused by yeast, and the remaining episodes were caused by Aspergillus spp. Age, sex, and education did not affect the FP incidence. Lupus patients (969 patient-months) had a higher incidence of FP than patients with other underlying diseases (p < 0.05). The 19 FP patients also had a higher incidence of bacterial peritonitis than other PD patients (p < 0.01). Among the 20 FP episodes, 14 (70%) were preceded by antibiotic use, and eight (40%) developed during hospitalization. Steroids were used at the time of FP in five of six lupus patients. Seven patients (37%) died within 1 month after diagnosis of FP. Five patients were able to remain on PD after FP, but only three patients were able to maintain catheter placement.

CONCLUSION

The risk factors for FP identified in this study include the use of antibiotics and steroids, underlying lupus, frequent occurrence of bacterial peritonitis, and hospitalization. Antifungal therapy may allow the catheter to be kept in place in a few patients, but catheter removal should be considered in patients whose FP is refractory to medical treatment.

Natural changes in peritoneal equilibration test results in continuous ambulatory peritoneal dialysis patients: a retrospective, seven year cohort survey

We conducted a retrospective, 7 year cohort survey to examine the natural changes in peritoneal equilibration test (PET) results in patients with long-term uneventful continuous ambulatory peritoneal dialysis (CAPD). Thirty-two (17 males, 15 females) patients on CAPD with two or more standard PETs performed more than 6 months apart, in the absence of peritoneal insult, were included. Changes and pattern of PET results were evaluated by the dialysate to plasma ratio of creatinine (D:P-cre), the fourth h dialysate to instilled glucose ratio (D4:Do) and ultrafiltration volume (UF, ml). The subgroups included high (H), high-average (HA), low-average (LA), or low (L) transporters with the dividing ratios (D:P-cre) of >0.81, >0. 65 to 0.81, >0.5 to 0.65, and <0.5, respectively. The median D:P-cre significantly decreased (p = 0.04), but neither the D4:Do nor the final median UF significantly decreased. The change in D:P-cre was strongly and inversely correlated with the initial D:P-cre value (r = -0.68; p < 0.05). A similar relationship was found between the change in the final D4:Do and the initial D4:Do (r = -0.752; p < 0. 01) and between the change in the final UF and the initial UF (r = -0.875; p < 0.01). No correlation was found between the change in D:P-cre and the age of the patient, the time interval between PETs, monthly dialysate glucose exposure, or underlying diabetes/non-diabetes. The final peritoneal transport pattern was altered with 5 (15.6%) patients remaining in the extreme subgroups (H or L) and, by contrast, 84.4% (27/32) of the patients now in the averaged (HA or LA) groups (p < 0.01, chi2 test). We demonstrated a natural "centralization" migration of PET results after long-term uneventful CAPD, which may help to explain why patients with extreme PET characteristics, that is, H or L, continued to do well on CAPD.

Necrotizing fasciitis caused by Serratia marcescens in two patients receiving corticosteroid therapy

Necrotizing fasciitis (NF), a devastating soft tissue infection, is rarely attributed to Serratia marcescens. We here report two patients with S. marcescens NF, both of whom had underlying renal disease and had been receiving corticosteroid therapy. The first patient, a 40-year-old man with systemic lupus erythematosus and uremia on prednisolone therapy, developed fulminant cellulitis and septic shock 1 month after a skin biopsy for cutaneous vasculitis of the left foot. The cellulitis evolved to NF, and blood and necrotic tissue cultures both grew S. marcescens. The patient completely recovered after debridement and ceftazidime therapy. The second patient, a 73-year-old man receiving prednisolone therapy for nephrotic syndrome, developed right leg cellulitis that evolved to NF. Blood and necrotic tissue cultures both grew S. marcescens. After aggressive debridement and ciprofloaxcin therapy, the NF improved. However, the patient died of aspiration pneumonia and massive gastrointestinal bleeding 1 month later. These findings illustrate that S. marcescens should be considered as a potential pathogen causing NF in susceptible hosts.

Impact of peritoneal membrane transport on technique failure and patient survival in a population on automated peritoneal dialysis

The peritoneal equilibration test (PET) is well established as a tool for classifying patients as low (L), low average (LA), high average (HA), or high (H) peritoneal transporters. We performed this retrospective 6 year cohort survey to evaluate the impact of different types of PET results on technique survival and patient survival on automated peritoneal dialysis (APD) therapy. From March 1992 to May 1998, 50 patients (20 men, 30 women) receiving APD were enrolled. The mean follow-up period was 25.2 +/- 9.2 months. Basic data and PET results of each patient at the initiation of APD therapy were retrospectively obtained for analysis. Adequacy of dialysis was estimated by measurement of total weekly urea clearance (Kt) normalized to total body water (V) and total weekly creatinine clearance (Ccr) per 1.73 m2 body surface area. The clinical outcomes evaluated were technique survival and patient survival. For statistical analyses we used the Kruskal-Wallis test, Friedman test, Kaplan-Meier life table analysis, and Cox's proportional hazards regression model. There were no differences in age, gender, prevalence of diabetes mellitus (DM), duration of APD, or the initial value of serum albumin between the four subgroups (H, HA, LA, and L). There were 11 (22%) deaths and 8 (16%) technique failures. The 2 year patient survival probability was significantly higher (100%) in the L subgroup than in the LA (62.6%), HA (48.4%), or H (46.2%) subgroups. Patients with DM had a lower patient survival rate than patients without DM; however, there was no statistical significance in technique survival rate between them. Diabetes mellitus (RR = 2.898) and the final albumin value (RR = 0.2099 per increase of 1 gm/dl) had a significant influence on patient survival. By stepwise regression analysis of final serum albumin levels, we found that patients with lower serum albumin values (< or = 3.0 gm/dl vs. >3.0 gm/dl) had a significantly lower probability of patient survival (p = 0.0156). We conclusively demonstrate four important findings in this work: 1) patients with H peritoneal transport had a lower probability of patient survival, but not a decreased rate of technique survival; 2) patients with L peritoneal transport can tolerate APD well; 3) there was no significant difference in technique survival rate between the different PET subgroups; and 4) DM and a lower serum albumin, implicating malnutrition, may contribute to the lower probability of patient survival among H peritoneal transporters.

GB virus C infection in hemodialysis patients: molecular evidence for nosocomial transmission

Studies of the prevalence and clinical relevance of GB virus C (GBV-C) infection in 328 hemodialysis (HD) patients were done, and the possibility of nosocomial GBV-C transmission was explored by molecular epidemiology methods. For GBV-C viremic patients in a given HD unit, nucleotide sequences of the envelope region were analyzed by phylogenetic tree constructions. Of 328 HD patients, active hepatitis B virus, hepatitis C virus (HCV), and GBV-C infection were detected in 13%, 23%, and 17%, respectively. Except for a higher frequency of HCV coinfection, the demographic and clinical characteristics of patients with and without GBV-C infection were comparable. In contrast, patients with isolated HCV infection had significantly higher serum transaminase levels, longer time on HD, and more blood transfusions. Phylogenetic analysis showed several distinct clusters of closely related GBV-C isolates from one HD unit, suggesting the possibility of nosocomial transmission. These results suggest that GBV-C plays a minimal role in causing hepatitis in Taiwanese HD patients and in nosocomial transmission.

GB virus C/hepatitis G virus infection in patients on continuous ambulatory peritoneal dialysis

BACKGROUND

GB virus C or hepatitis G virus (GBV-C/HGV) can be transmitted parenterally, very likely sharing common routes of transmission with hepatitis C virus (HCV). Patients on maintenance haemodialysis have been shown to be at increased risk of the novel GBV-C/HGV infection. Whether continuous ambulatory peritoneal dialysis (CAPD) can reduce the risk of GBV-C/HGV infection as demonstrated for HCV remains unknown.

METHODS

Serum GBV-C/HGV RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) with nested primers derived from the 5'-untranslated region (5' UTR) of the viral genome. We investigated the prevalence of GBV-C/HGV viraemia in 60 patients on CAPD and the possible routes of transmission. One hundred healthy adults were selected as controls.

RESULTS

The prevalence of GBV-C/HGV viraemia in CAPD patients was 23.3%, compared with 1% of healthy adults (P<0.05). Compared with patients without hepatitis B virus (HBV), HCV or GBV-C/HGV infection (n=39), those with GBV-C/HGV infection alone (n=11) have received more blood transfusions (mean 18.9 units vs 6.8 units, P<0.05). There were no significant differences between the viraemic and nonviraemic groups with respect to age, gender, duration of CAPD, duration of previous haemodialysis, previous history of surgery and co-infection with HBV or HCV. Three of the 11 (27.3%) patients with GBV-C/HGV infection alone had elevated serum alanine aminotransferase (ALT) level, and the frequency was significantly higher than that of patients negative for the viraemia (0%, P<0.05). In addition, the mean serum ALT level was also higher in the group with GBV-C/HGV infection compared with those without HBV, HCV and GBV-C/HGV infections (22.3+/-16.9 U/l vs 14.0+/-6.8 U/l, P<0.01).

CONCLUSIONS

Patients on CAPD are at increased risk of GBV-C/HGV infection, and the risk parallels the number of previously transfused units of blood.

Trace elements burden in geriatric hemodialysis patients: a prospective multicenter collaborative study

INTRODUCTION

Hemodialysis therapy and the aging process have been reported to interfere with the trace element (TE) status in the body. This multicenter collaborative study on blood levels of TE in geriatric hemodialysis (HD) patients was carried out with an aim to clarify the impact of the aging process and HD therapy on the TE status in such patients.

METHODS

One hundred and fifty-one HD patients (65 male, 86 female), all aged over 60 (68.2+/-3.86 y), and 112 elderly controls (58 male, 54 female) with a mean age of 67.5+/-3.03 were enrolled. All patients underwent standard HD for at least 6 months. The artificial kidneys used were hollow-fiber dialyzers of cellulose membranes. Water used for HD was prepared by reverse osmosis. Blood was collected in the morning prior to dialysis and after fasting. Atomic absorption spectrophotometry was applied to measure blood levels of Pb, Cd and Hg as well as plasma levels of Cu, Zn and Al. Data are presented as mean +/- SEM. Student's t-test and linear regression were applied for statistics.

RESULTS

Our geriatric chronic HD patients showed a marked elevation of blood Al and decreased plasma Zn concentrations. The blood levels of Cu, Cd, Pb and Hg were within normal limits. The blood concentrations of Al, Cu and Pb were significantly higher in HD patients than in the normal elderly controls, whereas Cd and Hg were similar in both groups, and Zn were lower in HD patients. Plasma Zn value decreased as dialysis duration increased, however there was a reversely linear correlation between plasma Zn and age.

CONCLUSIONS

This data reported can be regarded as a starting point and may serve as an insight to further studies on TE imbalances in geriatric and chronic HD populations.

Revised cutoff values of serum aminotransferase in detecting viral hepatitis among CAPD patients: experience from Taiwan, an endemic area for hepatitis B

BACKGROUND

To determine the best cutoff values of aspartate aminotransferase (AST) and alanine amino-transferase (ALT) in detecting viral hepatitis C infection among patients of continuous ambulatory peritoneal dialysis (CAPD).

METHODS

90 (44 male and 46 female) CAPD patients and 526 adult controls (266 male, 260 female) were enrolled. Serum AST and ALT were measured by an auto-analyser monthly. Serum HBsAg was examined using a RIA method and anti-HCV by an second-generation EIA method. The best cutoff values of AST and ALT for detecting viral hepatitis were obtained from the ROC (receiver-operating characteristic) curve.

RESULTS

The prevalence of anti-HCV(+) was significantly higher in CAPD patients (16.7%) than in normal controls (4.9%), while that of HBsAg(+) was similar in both groups. CAPD patients had significantly lower levels of serum aminotransferases compared to normal controls. Mean AST were 23.8 IU/l in normal control and 18.8 IU/l in the CAPD patients (P < 0.001). Mean ALT were 21.9 IU/l in normal controls and 15.3 IU/l in the CAPD patients (P < 0.001). CAPD patients with HCV infection had higher serum AST and ALT levels than those without. However, HBV infection did not cause significant serum aminotransferase elevation in patients. The conventional cutoff values of AST (40 IU/l) and ALT (40 IU/l) for detecting viral hepatitis yielded only a sensitivity of 27.3 and 18.2% respectively; on the contrary, our revised cutoff values of AST (24 IU/l) and ALT (17 IU/l) had better sensitivities (AST, 72.7%; ALT, 63.6%). For serial aminotransferase values, the sensitivity of AST and ALT for detecting HCV were 36.4 and 27.3% by conventional criteria, and were both 81.8%, by our newly revised criteria.

CONCLUSIONS

Serum aminotransferase cutoff values should be modified for screening viral hepatitis in a CAPD population. Our new cutoff criteria had important clinical implications in providing benefits of earlier detection and possible prevention from chronic hepatic deteriorations.

Viral hepatitis in continuous ambulatory peritoneal dialysis patients in an endemic area for hepatitis B and C infection: the Taiwan experience

The prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and their associations in 64 continuous ambulatory peritoneal dialysis (CAPD) patients (30 males and 34 females) were evaluated. A comparison was also made with 526 normal controls (266 males and 260 females). Forty-seven (75%) CAPD patients were anti-HBc positive, with no significant difference to the control group (81.9%). This probably reflects acquisition of HBV infection by CAPD patients before initiation of chronic dialysis therapy in a region hyperendemic for HBV. On the contrary, 11 (17.2%) CAPD patients were anti-HCV positive and 8 (15.2%) were seropositive for both anti-HBc and anti-HCV-much greater prevalence rates compared to those of the control group. The prevalence of anti-HCV correlated with the history and numbers of blood transfusion, and the length of time on previous hemodialysis. A similar correlation occurred in patients with both anti-HBc(+) and anti-HCV(+). In conclusion, in an HBV endemic area such as Taiwan, the prevalence of coexisting HBV and HCV infection in CAPD patients depends on the latter.

Adult primary IgA nephropathy and common viral infections

Serum samples obtained from 69 histopathologically proven IgA nephropathy (IgAN) patients and 563 healthy controls were examined to evaluate the association between IgAN and common viral infections. Antibody titres to cytomegalovirus (CMV), herpes simplex virus (HSV), Vericella-Zoster virus (VZV), Influenza A (Inf. A) and Influenza B (Inf. B) viruses were determined, using a complement fixation test. The viral antibody titres were considered to be positive with dilutions of 1:8 or greater except for Epstein-Barr virus (EBV), studied using immunofluorescence, which was considered to be positive with dilutions of 1:10 or greater. The positive rate of Inf. B antibody in IgAN patients was significantly lower than that in controls. The frequency of positive CMV antibody titres was higher than for controls, but with only borderline statistical significance (P = 0.059). The frequency of positive CMV and Inf. B titres was compared by age in IgAN patients and controls. but showed no statistically significant difference. Comparisons of percentage distributions at each antibody dilution level to the common virus of IgAN patients and controls, but showed no statistically significant difference. Comparisons of percentage distributions at each antibody dilution level to the common virus of IgAN patients and controls were made; however, none showed a statistically significant difference. In conclusion, no absolutely higher frequency of positive antibody titres for common viruses was demonstrated in IgAN patients in this study.

Effects of intraperitoneal antibiotics on human peritoneal mesothelial cell growth

Peritonitis is one of the most frequent complications of continuous ambulatory peritoneal dialysis (CAPD). Necrosis and exfoliation of the mesothelial cell layer of the peritoneum develop during the acute phase of peritonitis. Agents that hamper regeneration of mesothelial cells will cause delayed recovery of the peritoneal surface, which results in continuous exposure of underlying stem cells to the stimulation of growth factors and possibly leads to peritoneal fibrosis syndrome. The aim of the present study is to determine the effects of several intraperitoneal antibiotics on human peritoneal mesothelial cell (HPMC) growth at their usual loading and maintenance doses. HPMCs were isolated from human omenta. Proliferation of HPMC was evaluated by modified methyltetrazolium assay and cell membrane integrity was assessed by lactate dehydrogenase method. The results showed that most cephalosporins exert an inhibitory, even toxic, effect on HPMCs at their loading doses. Cephalothin, cephradine, cefamandole, cefoxitin, cefuroxime and cefoperazone inhibited HPMC proliferation at their maintenance doses. Vancomycin, clindamycin, aztreonam, piperacillin, imipenem, tobramycin and ceftriaxone have no effect in their usual intraperitoneal doses. From the viewpoint of peritoneal protection, not only drug sensitivity of the causative microorganisms but also effects of antibiotics on HPMC regeneration should be considered when selecting antibiotics for CAPD peritonitis.

Quantitative analysis of messenger ribonucleic acid encoding natriuretic peptide receptors in aldosterone-producing adenoma

There exist conflicting data regarding the inhibitory effect of atrial natriuretic peptide on aldosterone production from aldosterone-producing adenoma (APA). Natriuretic peptides mediate their actions through natriuretic peptide receptors (NPRs). Whether or not NPRs are present in the tumors remains controversial. To elucidate this paradox, gene expression of NPRs was examined by Northern blot analysis and competitive polymerase chain reaction in tumorous and non-tumorous portions of APA, and in normal adrenal gland from patients with renal cell carcinoma. The results of Northern blot analysis showed the presence of messenger ribonucleic acid (mRNA) of three NPRs in all adrenal tissues, including APA. The proportional expression of NPR gene transcripts in APA was type A (0.6%), type B (18.7%), and type C (80.7%). The levels, but not the proportions, of type C and possibly type B NPR mRNAs were lower in tumorous and non-tumorous portions of APA compared to those in normal adrenal gland (type C 190.2 +/- 24.5 [means +/- SEM, normal adrenal gland] > 168.1 +/- 20.8 [non-tumorous portion] > 112.2 +/- 15.5 [tumorous portion] pg/10 micrograms total RNA, F = 3.82, P < 0.05; type B 45.2 +/- 8.5 [normal adrenal gland] > 30.0 +/- 5.2 [non-tumorous portion] > 25.1 +/- 4.1 [tumorous portion] pg/10 micrograms total RNA, F = 3.03, P = 0.065). The mRNA levels of type C, rather than type A or type B, NPR were correlated with the percentage of zona fasciculata-like cells in APA (r = 0.90, P < 0.05). In conclusion we have demonstrated the presence of mRNA encoding the three NPRs in APA.(ABSTRACT TRUNCATED AT 250 WORDS)

Zona fasciculata-like cells determine the response of plasma aldosterone to metoclopramide and aldosterone synthase messenger ribonucleic acid level in aldosterone-producing adenoma

The different responses of plasma aldosterone to ACTH and angiotensin II in aldosterone-producing adenoma (APA) is thought to be due to the various cellular compositions of the tumors. To investigate whether the dopaminergic regulation of aldosterone in APA is also dependent on the cellular types, we studied the effects of metoclopramide on plasma aldosterone in six patients with APA. The messenger RNA (mRNA) levels of aldosterone synthase (P450aldo), 11 beta-hydroxylase (P450(11) beta), and 17 alpha-hydroxylase (P450(17) alpha) of APA and normal adrenal glands were determined by competitive polymerase chain reaction. After administration of metoclopramide (an antagonist of dopamine-2 receptor), the increment of plasma aldosterone correlated inversely with the percentage of zona fasciculata cells of APA. The mRNA level of P450aldo in the tumorous portion was much higher, whereas the levels of P450(11) beta and P450(17) alpha mRNAs were lower, than those of the nontumorous portion and normal adrenals. There was a correlation of the percentage of zona fasciculata cells in APA with the levels of P450aldo and P450(11) beta mRNAs, but not with P450(17) alpha mRNA. These results suggest that differential responsiveness of plasma aldosterone to metoclopramide may be due to various proportions of different cell types in APA that may have different expression of dopamine-2 receptor. In addition, this histologically dependent expression was present at the transcriptional level of the gene responsible for aldosterone biosynthesis.

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.

Non-excretory myeloma with diffuse osteolytic lesions caused by tumor necrosis factor: report of a case

A 63-year-old male patient was admitted to the hospital after a six-month complaint of low back pain. Anemia, hypercalcemia and 5 to 18% giant abnormal binucleated plasma cells infiltrations in the bone marrow suggested a diagnosis of multiple myeloma. However, repeated serum and urine immunofixation electrophoresis failed to demonstrate any abnormal monoclonal band. Diagnosis of non-excretory myeloma was verified by immunocytochemical stains demonstrating intracellular kappa chain in these neoplastic cells. Some authors have claimed that there were fewer bone lytic changes, less bone marrow infiltration, more preservation of normal immunoglobulin but with more neurological presentations among non-excretors. However, this patient had severely generalized bone lytic lesions and high serum level of tumor necrosis factor. The former might be attributed to the latter. Literatures about multiple myeloma and the tumor necrosis factor are also reviewed.