Epidemiologic trends in chronic renal replacement therapy over forty years: a Swiss dialysis experience.

BACKGROUND: Long term longitudinal data are scarce on epidemiological characteristics and patient outcomes in patients on maintenance dialysis, especially in Switzerland. We examined changes in epidemiology of patients undergoing renal replacement therapy by either hemodialysis or peritoneal dialysis over four decades. METHODS: Single center retrospective study including all patients which initiated dialysis treatment for ESRD between 1970 and 2008. Analyses were performed for subgroups according to dialysis vintage, based on stratification into quartiles of date of first treatment. A multivariate model predicting death and survival time, using time-dependent Cox regression, was developed. RESULTS: 964 patients were investigated. Incident mean age progressively increased from 48 ± 14 to 64 ± 15 years from 1st to 4th quartile (p < 0.001), with a concomitant decrease in 3- and 5-year survival from 72.2 to 67.7%, and 64.1 to 54.8%, respectively. Nevertheless, live span continuously increased from 57 ± 13 to 74 ± 11 years (p < 0.001). Patients transplanted at least once were significantly younger at dialysis initiation, with significantly better survival, however, shortened live span vs. individuals remaining on dialysis. Among age at time of initiating dialysis therapy, sex, dialysis modality and transplant status, only transplant status is a significant independent covariate predicting death (HR: 0.10 for transplanted vs. non-transplanted patients, p = 0.001). Dialysis vintage was associated with better survival during the second vs. the first quartile (p = 0.026). DISCUSSION: We document an increase of a predominantly elderly incident and prevalent dialysis population, with progressively shortened survival after initiation of renal replacement over four decades, and, nevertheless, a prolonged lifespan. Analysis of the data is limited by lack of information on comorbidity in the study population. CONCLUSIONS: Survival in patients on renal replacement therapy seems to be affected not only by medical and technical advances in dialysis therapy, but may mostly reflect progressively lower mortality of individuals with cardiovascular and metabolic complications, as well as a policy of accepting older and polymorbid patients for dialysis in more recent times. This is relevant to make demographic predictions in face of the ESRD epidemic nephrologists and policy makers are facing in industrialized countries.

Variable intrafamilial expressivity of the rare tumor necrosis factor-receptor associated periodic syndrome-associated mutation I170N that affects the TNFR1A cleavage site.

We report on a 33-year-old female patient with a relatively mild clinical case of TNF-receptor associated periodic syndrome (TRAPS) and her 58-year-old father in whom end-stage renal disease due to TRAPS-related AA-amyloidosis has already developed. TRAPS was caused by a I170N mutation that has previously not been associated with amyloidosis. It remains unclear if an only mildly affected patient such as ours would benefit from treatment considering her father's severe course of disease. The relevant literature on this problem is reviewed.

Dose-related influence of sodium selenite on apoptosis in human thyroid follicles in vitro induced by iodine, EGF, TGF-beta, and H2O2.

Apoptosis of thyroid follicular cells is induced by high doses of iodide, epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), as well as H2O2 and might be attenuated by antioxidants. Therefore, we examined the apoptotic index induced by these substances in selenium-treated vs untreated human thyroid follicular cells. Reconstituted human thyroid follicles were incubated with sodium selenite (10 or 100 nM) for 72 h; controls received none. The follicles were then distributed to 24-well plates and incubated with potassium iodide (5, 10, or 20 nM), EGF (5 ng/mL), TGF-beta (5 ng/mL), or H2O2 (100 muM). Apoptosis was determined by a mitochondrial potential assay and the number of apoptotic cells counted by two independent, experienced technicians and the glutathione peroxidase (GPx) activity was determined. Asignificant increase of apoptic cells was obtained in control thyroid follicles treated with iodine (5, 10, or 20 microM), thyroidstimulating hormone (TSH) 1, or 10 mU/mL in combination with 5 and 10 microM iodine, EGF (5 ng/mL) and TGF-beta (5 ng/mL), or H2O2 (100 microM) (p < 0.001). In contrast, in thyroid follicles preincubated with 10 or 100 nM sodium selenite, the apoptototic index was identical to the basal rate. In H2O2-treated follicles, the apoptotic index was still significantly elevated but 50% lower compared to control cells. The GPx activity increased from 1.4 +/- 0.2 to 2.25 +/- 0.4 mU/microg DNA with 10 nMselenite and 2.6 + 0.4 mU/microg DNA with 100 nM selenite. Sodium selenite might increase the antioxidative potential in human thyroid follicles in vitro and therefore diminish the apoptosis induced by TGF-beta, EGF, iodide, and even H2O2.

The functional domains of the chloroplast unusual positioning protein 1.

Chloroplasts of plants move in response to variations in light intensity. One protein involved in this process is the chloroplast unusual positioning protein 1-CHUP1, which is anchored in the outer membrane of the organelle. The protein is able to interact with actin and profilin and might coordinate actin filament reformation and thereby chloroplast repositioning. However, molecular details on this action have not been presented so far. Here, we demonstrate that CHUP1 is able to homo-dimerize and that this dimerization is dependent on the N-terminal coiled-coil domain. The leucine zippers, which are present in the N-terminal and C-terminal portion of the protein, are involved in the formation of intra-molecular interactions. Based on this we propose that CHUP1 functions as a dimer and that intra-molecular structure formation might result in a close proximity of the proline rich domain involved in profilin binding and the actin binding domain.

18F-FDG PET as a diagnostic procedure in large vessel vasculitis-a controlled, blinded re-examination of routine PET scans.

Large vessel vasculitis can be visualized by 18F-FDG positron emission tomography (PET). However, the diagnostic value of 18F-FDG PET is yet to be determined. We therefore performed a study to evaluate this technique for the diagnosis of giant cell arteritis (GCA) and Takayasu arteritis (TA). Patients with GCA or TA, who fulfilled the American College of Rheumatology (ACR) criteria and also had a pathologic PET scan in clinical routine, were selected. These PET scans, as well as PET scans obtained from age- and sex-matched control patients, were independently re-evaluated by two experienced nuclear medicine experts. PET scans of 20 patients (17 GCA, 3 TA) and 20 controls were evaluated. In 85% of the examinations, both observers agreed on the diagnosis or exclusion of vasculitis. Specificity was calculated with 80% and sensitivity with 65%, yielding an overall diagnostic accuracy of 72%. The mean maximum standardized uptake values (SUVmax) of the subclavian region was significantly higher in vasculitis than in control patients (2.77 ± 1.02 vs 2.09 ± 0.64; difference 0.69; CI(95%): 0.14-1.24, p = 0.0161). SUVmax of the iliacal regions did not differ significantly. Receiver- operating characteristics (ROC) analysis revealed the highest sensitivity of 90% (CI(95%): 68-99%) and specificity of 45% (CI(95%): 23-69%) for a SUVmax cut-off point of 1.78 (AUC 0.72, (CI(95%): 0.56-0.86). PET findings are reproducible and independent of the observer. The low sensitivity and specificity indicate that enhanced vascular uptake might be overrated if clinical details are suggestive for vasculitis. Therefore, the diagnosis of large vessel vasculitis should not be based on PET findings only.

Estrogen receptor alpha expression in podocytes mediates protection against apoptosis in-vitro and in-vivo.

CONTEXT/OBJECTIVE: Epidemiological studies have demonstrated that women have a significantly better prognosis in chronic renal diseases compared to men. This suggests critical influences of gender hormones on glomerular structure and function. We examined potential direct protective effects of estradiol on podocytes. METHODS: Expression of estrogen receptor alpha (ERα) was examined in podocytes in vitro and in vivo. Receptor localization was shown using Western blot of separated nuclear and cytoplasmatic protein fractions. Podocytes were treated with Puromycin aminonucleoside (PAN, apoptosis induction), estradiol, or both in combination. Apoptotic cells were detected with Hoechst nuclear staining and Annexin-FITC flow cytometry. To visualize mitochondrial membrane potential depolarization as an indicator for apoptosis, cells were stained with tetramethyl rhodamine methylester (TMRM). Estradiol-induced phosphorylation of ERK1/2 and p38 MAPK was examined by Western blot. Glomeruli of ERα knock-out mice and wild-type controls were analysed by histomorphometry and immunohistochemistry. RESULTS: ERα was consistently expressed in human and murine podocytes. Estradiol stimulated ERα protein expression, reduced PAN-induced apoptosis in vitro by 26.5±24.6% or 56.6±5.9% (flow cytometry or Hoechst-staining, respectively; both p<0.05), and restored PAN-induced mitochondrial membrane potential depolarization. Estradiol enhanced ERK1/2 phosphorylation. In ERα knockout mice, podocyte number was reduced compared to controls (female/male: 80/86 vs. 132/135 podocytes per glomerulus, p<0.05). Podocyte volume was enhanced in ERα knockout mice (female/male: 429/371 µm(3) vs. 264/223 µm(3) in controls, p<0.05). Tgfß1 and collagen type IV expression were increased in knockout mice, indicating glomerular damage. CONCLUSIONS: Podocytes express ERα, whose activation leads to a significant protection against experimentally induced apoptosis. Possible underlying mechanisms include stabilization of mitochondrial membrane potential and activation of MAPK signalling. Characteristic morphological changes indicating glomerulopathy in ERα knock-out mice support the in vivo relevance of the ERα for podocyte viability and function. Thus, our findings provide a novel model for the protective influence of female gender on chronic glomerular diseases.

Der1-mediated preprotein import into the periplastid compartment of chromalveolates?

Phototrophic chromalveolates possess plastids surrounded by either 3 or 4 membranes, revealing their secondary endosymbiotic origin from an engulfed eukaryotic alga. In cryptophytes, a member of the chromalveolates, the organelle is embedded within a designated region of the host's rough endoplasmic reticulum (RER). Its eukaryotic compartments other than the plastid were reduced to the mere remains of its former cytosol, the periplastid compartment (PPC, PP space), and its nucleus, the nucleomorph, separated from the RER by its former plasma membrane, the periplast membrane (PPM). In the nucleomorph genome of the cryptophyte Guillardia theta, we identified several genes sharing homology with components of the ER-associated degradation (ERAD) machinery of yeast and higher eukaryotes, namely ORF201 and ORF477, homologs of membrane-bound proteins, Der1p (Degradation in the ER protein 1) and the RING-finger ubiquitin ligase Hrd1, and a truncated version of Udf1, a cofactor of Cdc48, a lumenal ATPase. Exemplarily, studies on the Der1-homolog ORF201 showed that this protein partially rescued a yeast deletion mutant, indicating the existence of a functional PPC-specific ERAD-like system in cryptophytes. With the noninvestigated exception of haptophytes a phylogenetically and mechanistically related system is apparently present in all chromalveolates with 4 membrane-bound plastids because amongst others, PPC-specific Derlins (Der1-like proteins), CDC48 and its cofactor Ufd1 were identified in the nuclear genomes of diatoms and apicomplexa. These proteins are equipped with the required topogenic signals to direct them into the periplastid compartment of their secondary symbionts. Based on our findings, we suggest that all chromalveolates with 4 membrane-bound plastids express an ERAD-derived machinery in the PPM of their secondary plastid, coexisting physically and systematically adjacent to the host's own ERAD system. We propose herewith that this system was functionally adapted to mediate transport of nucleus-encoded PPC/plastid preproteins from the RER into the periplastid space.