[Juvenile idiopathic epiretinal membrane]. / Juvenile idiopathische epiretinale Membran.

Idiopathic epiretinal membrane (iERM) is very rare in adolescent patients. The pathogenesis remains unclear although the role of hyalocytes is of major importance. The clinical features in young patients are different from those in older patients. We describe a case of iERM in a 15-year-old girl who presented with metamorphopsia of the right eye. This case report presents the basis for the decision for surgical treatment as well as the clinical features at follow-up examination 9 months after surgery.

[Surgical treatment of neovascular glaucoma]. / Operative Therapie des Neovaskularisationsglaukoms.

PURPOSE: The neovascular glaucoma is one of the leading causes for an enucleation. The cyclocryocoagulation, the peripheral retinal cryocoagulation and the intravitreal injection of bevacizumab as combined therapy aim at the reduction of the intraocular pressure and of neovascularisation. MATERIALS AND METHODS: This study follows up 135 patients with neovascular glaucoma who underwent the above-mentioned combined therapy consisting of cyclocryocoagulation, peripheral retinal cryocoagulation and intravitreal injection of bevacizumab. RESULTS: The most common causes of neovascular glaucoma in our study are diabetic retinopathy and central retinal vein occlusion. The intraocular pressure was 37.4 mmHg (± 15.8) mmHg preoperatively under maximum antiglaucomatous therapy and was reduced to 19.0 (± 8.5) mmHg direct postoperatively. In the long-term intraocular pressure remained within the normal range in 93.33 % of patients. A successful reduction of the local antiglaucomatous drops of 1.9 substances to 1.7 substances was observed after 3 months. The oral intake of acetazolamide was also statistically significantly reduced. 47.37 % of the patients were normotensive without local therapy and only 3 patients were still on acetazolamide even after 1 year. The most serious complication was a phthisis bulbi in 1.5 % of patients. Overall 98.5 % of patients remained free of pain and maintained visual acuity after the end of the follow-up. CONCLUSION: Long-term pressure regulation and freedom from pain were successfully achieved. For decompensated neovascular glaucoma with poor vision and painful bulb, the combination of retinal cryocoagulation and intravitreal application of bevacizumab is an important therapeutic option.

[Endoresection of large uveal melanomas after pretreatment by single-dose stereotactic convergence irradiation with the leksell gamma knife--first experience on 46 cases]. / Endoresektion grosser Melanome der Uvea nach stereotaktischer Single-dose-Vorbestrahlung mit dem Leksell Gamma-Knife -- Erste Erfahrungen an 46 Fällen.

BACKGROUND: The aim of this non-comparative, consecutive case series is to evaluate the short-term results after endoresection of large uveal melanomas in combination with pretreatment with stereotactic gamma knife radiosurgery. METHODS: Between March 2000 and November 2002, forty-six patients with large uveal melanomas underwent stereotactic radiosurgery followed by endoresection of the tumour via a standard three-port vitrectomy including laser photocoagulation and silicone oil tamponade. The average tumour height was 9.5 mm. The minimum dose delivered to the tumour volume was 25 Gy. RESULTS: The median follow-up time was 410 days. In 40 cases (87 %), the eye was retained with a VA of 20/200 or better in 30 cases (65.2 %) and 20/63 or better in ten cases (21.7 %). In 12 eyes with a follow-up of >/= 0.5 years, the median VA was 20/80 after silicone oil removal and cataract surgery had been performed. Six eyes (13 %) were enucleated due to serious complications caused by the radiosurgery (3 cases) or endoresection (3 cases). In 13 patients (28.2 %), additional major surgery was required. Seven patients developed liver metastases during follow-up and six patients died. No local tumour recurrences were observed. CONCLUSIONS: Eyes with large uveal melanomas can be salvaged by stereotactic radiotherapy followed by endoresection.

Ruthenium-106 plaque brachytherapy for symptomatic vasoproliferative tumours of the retina.

AIM: To investigate the safety and efficacy of beta ray brachytherapy in treatment of vasoproliferative tumours of the retina (VTR). METHODS: 35 consecutive patients with symptomatic VTR were treated with a ruthenium-106 ((106)Ru) plaque. Three tumours had been treated previously (two with cryotherapy; one with transpupillary thermotherapy). 32 VTR (91.4%) were located in the lower half of the retina and all of them were found between the mid-periphery and the ora serrata. The mean tumour thickness was 2.8 mm. An exudative retinal detachment was present in 25 eyes (71.4%) and in 15 cases (42.9%) hard exudates were found in the macula. The major symptom was loss of vision (77.1%). RESULTS: Brachytherapy was well tolerated by every patient. The mean applied dose was 416 Gy at the sclera and 108 Gy at the tumour apex. In all but four eyes (88.6%), it was possible to control the VTR activity. The median follow up time was 24 months. Three of the above mentioned four eyes with treatment failure had had secondary glaucoma before therapy. There was no case of radiation induced neuropathy or retinopathy. Cataract surgery was necessary for five patients. The development of epiretinal gliosis was the most common event during follow up (n = 10, 28.6%). The mean visual acuity decreased slightly (0.33 before and 0.29 after brachytherapy). Multivariate analysis showed that the presence of macular pathology before treatment was associated with a 6.1-fold risk of vision of 0.25 or better (p = 0.03). CONCLUSIONS: beta ray brachytherapy with (1106)Ru plaques was able to control the activity of VTR and retain vision. Cases with secondary glaucoma before treatment had a very poor prognosis.

Photodynamic therapy using verteporfin in circumscribed choroidal haemangioma.

AIM: To investigate the safety and efficacy of photodynamic therapy with verteporfin in patients with choroidal haemangioma. METHODS: A non-randomised, prospective clinical investigation of 19 patients with symptomatic circumscribed choroidal haemangioma was performed. Unsuccessful pretreatment (external beam irradiation, laser photocoagulation) was performed in four patients. Patients were included when (1) subretinal exudation involving the fovea, (2) a decrease in visual function, and (3) additional symptoms (for example, metamorphopsia) were present. Photodynamic therapy (PDT) was performed with verteporfin at a concentration of 6 mg/m(2) body surface area and a light dose of 100 J/cm(2) at 692 nm. RESULTS: The mean follow up time was 10.6 months (2-24 months). The mean number of treatment sessions was 2.15 (range 1-5). Visual acuity improved by at least one line in 73.3%, by at least two lines in 42.1%, was stable in 21.1%, and decreased by one line in 5.2% of the patients. Exudation was completely resolved in 94.8% of the cases. Regression of tumour height was documented in all 19 tumours. Patients receiving any pretreatment before PDT, a visual acuity of 0.1 and less, a history of more than 30 months, and no significant response after the first PDT session, did not show any significant improvement. Cox regression analysis revealed that the number of PDT treatment sessions was inversely associated with the improvement in visual acuity of at least two lines. No recurrences and no local or systemic side effects were observed during the follow up time. CONCLUSION: PDT using verteporfin is a safe and effective therapy for the treatment of symptomatic choroidal haemangioma even in tumours located beneath the fovea.

Solutions for APD: special considerations.

Automated peritoneal dialysis (APD) has become the fastest growing dialysis modality in Europe and the United States in recent years. Freedom from daytime exchanges, flexibility of prescription, performance in recumbent position leading to enhanced treatment efficacy, and a decreased incidence of peritonitis are the main advantages of APD over CAPD. Studies on new developments of glucose-based PD fluids were performed predominantly in CAPD patients. High volumes and frequent APD cycles in patients may aggravate the adverse effects of standard CAPD fluids on the peritoneal membrane with increasing time on PD. New, glucose-based PD fluids with neutral pH, very low concentrations of glucose degradation products (GDPs), containing either lactate or bicarbonate as buffering substances have been introduced into clinical use recently. With these new fluids, various in vitro, ex vivo, and in vivo studies could demonstrate a better preservation of peritoneal cell viability and growth, less inhibited secretory cell functions, a significant reduction in the formation of advanced glycation end products (AGEs), and clinical signs for an improved preservation of peritoneal mesothelial cells indicated by an increase in effluent CA125. One has to be aware, however, that uremia per se prior to initiation of PD, as well as during PD treatment itself, directly impacts on peritoneal membrane structural changes so that new, more biocompatible PD fluids may not be completely sufficient to prevent morphologic and functional changes of the membrane. Due to a strong sodium sieving during APD, PD fluids with sodium concentrations of 125-130 mmol/L may be beneficial. Systematic calcium kinetic studies have not yet been performed in APD patients. APD fluids should offer a calcium concentration range of 1.0-1.75 mmol/L in order to enable an individualized APD prescription. For long-term APD treatment, better knowledge of peritoneal membrane physiology and PD kinetics should promote individualization of prescriptions. New, pH-neutral PD solutions with minimized amounts of GDPs may be a significant step forward to improved membrane preservation during long-term APD treatment.

[Endoscopic resection of malignant melanomas of the uvea after preoperative stereotactic single dose convergence irradiation with the Leksell gamma knife]. / Endoresektion maligner Melanome der Uvea nach präoperativer stereotaktischer Einzeldosis-Konvergenzbestrahlung mit dem Leksell-Gamma-knife.

In cases of large volume and highly prominent melanomas of the uvea, it is rare for conventional methods of radiation therapy to enable salvage of the globe or even residual functionality of the affected eye. Complications due to the massive amount of accumulated necrotic tissue often necessitate subsequent enucleation of the blinded eye. Tumor-destroying, single-dose convergence irradiation (radiosurgery) of such tumors applied shortly before endoresection can represent a possible therapeutic alternative in these types of cases.

Expression of Fas and Fas ligand in uveal melanoma: biological implication and prognostic value.

The interaction between Fas and Fas ligand is one possible immune escape mechanism used by tumour cells. In the present study, melanoma tissue from 103 patients who underwent enucleation for malignant uveal melanoma (iris melanomas excluded) was stained by immunohistochemistry with monoclonal antibodies specific for Fas, Fas ligand, CD3, CD8, and CD68. Histological and clinical data for these tumours were assessed. Both Fas and Fas ligand were detected in uveal melanomas. Cells of the monocyte/macrophage lineage rather than T-cells were the predominant group of tumour-infiltrating cells. The metastasis-free 5-year survival rates in the univariate analyses were considerably lower in patients with tumours that lacked Fas ligand expression (< 35% of the tumour cells), in the presence of more than 50 CD8-positive cells in 20 high-power fields and in the presence of more than 100 CD3-positive cells in 20 high-power fields. Fas and Fas ligand expression was associated with scleral infiltration. After adjustment for scleral infiltration, the predictive value of both Fas and Fas ligand expression was markedly decreased. In addition, the CD3- and CD8-positive cell count was positively associated with the histological cell type. Cox proportional hazards models showed that the presence of CD3- and CD8-positive cells was not an independent prognostic factor after adjusting for histological cell type. This preliminary observation deserves further investigation, which may shed more light on the immune escape mechanisms of this tumour and thus enable novel therapeutic strategies. The clinical relevance of this observation is limited, as more predictive parameters have been described for uveal melanoma.

Partial deletions of the long and short arm of chromosome 3 point to two tumor suppressor genes in uveal melanoma.

Uveal melanoma is the most common form of primary eye cancer. Monosomy 3, which is an unusual finding in tumors but is present in approximately 50% of uveal melanomas, is significantly correlated with metastatic disease. To obtain positional information on putative tumor suppressor genes on this chromosome, we have investigated tumors from 333 patients by comparative genomic hybridization, microsatellite analysis, or conventional karyotype analysis. A partial deletion of the long arm was found in eight tumors, and the smallest region of deletion overlap (SRO) spans 3q24-q26. We found six tumors with a partial deletion of the short arm and were able to define a second SRO of about 2.5 Mb in 3p25. This SRO does not overlap with the VHL gene. Our finding suggests a role for two tumor suppressor genes in metastasizing uveal melanoma and may explain the loss of an entire chromosome 3 in these tumors.

Influence of neutral-pH dialysis solutions on the peritoneal membrane: a long-term investigation in rats.

OBJECTIVE: Glucose degradation products (GDPs) and low pH are potential causes of bioincompatibility of peritoneal dialysis fluids (PDFs). The aim of the present study was to compare the effect of 6 weeks' exposure of the peritoneum in rats to two different PDFs: a standard PDF with a low pH and high level of GDPs (CAPD 3: Fresenius Medical Care, Bad Homburg, Germany), and a modified PDF with a low level of GDPs and a physiologic pH (CAPD 3 Balance: Fresenius Medical Care). METHODS: After catheter implantation, rats were exposed twice daily for 6 weeks to CAPD 3 fluid or to CAPD 3 Balance. At the beginning and at the end of the study, a 4-hour dwell was performed in every rat to evaluate intraperitoneal inflammation and its effect on total collagen synthesis in the in vitro cultured rat mesothelial cells (ex vivo study). Additionally, after 6 weeks' exposure, the peritoneal cavity was opened, and macroscopic changes were evaluated according to a semiquantitative scale. Peritoneal samples were also taken for morphology study. RESULTS: In rats treated with CAPD 3 fluid, intraperitoneal inflammation was comparable at the beginning and at the end of the experiment. In animals exposed to CAPD 3 Balance, the intensity of the intraperitoneal inflammation decreased during the study (cell count, p = 0.0781; neutrophil:macrophage ratio, p < 0.01; nitrite concentration, p < 0.05; hyaluronan level, p < 0.05). The capacity of effluent dialysate from CAPD 3 rats to activate collagen synthesis in in vitro-cultured mesothelial cells was the same at the beginning and at the end of the study. In the CAPD 3 Balance group, this capacity was statistically significantly lower at the end of the study than at the beginning (p < 0.05). The mean thickness of the visceral peritoneum was comparable in both groups of animals, but, macroscopically, more severe fibrosis was found in the peritoneum of rats exposed to CAPD 3 as compared with animals treated with CAPD 3 Balance (p < 0.05). CONCLUSION: We showed that, in the rat model of peritoneal dialysis, chronic exposure of the peritoneum to PDFs with low GDPs and a physiologic pH diminished the intraperitoneal inflammatory reaction induced by dialysis, and reduced peritoneal fibrosis.

High glucose dialysis solutions increase synthesis of vascular endothelial growth factors by peritoneal vascular endothelial cells.

OBJECTIVE: Increased peritoneal vasculature has been reported in long-term peritoneal dialysis (PD), and vascular endothelial growth factors (VEGFs) have been found in dialysate. High concentrations of glucose or lactate, glucose degradation products (GDPs), and low pH of dialysis solutions are all possible factors in increased peritoneal VEGF synthesis. In this study, we investigated the effects of high glucose dialysis solutions on VEGF synthesis by peritoneal vascular endothelial cells (PVECs). METHODS: The PVECs were isolated from rat omentum and were incubated for 4 hours in three different culture media [M199 media (control), conventional dialysis solutions containing 4.25% glucose diluted with an equal volume of M199 media (HGD), and M199 media containing 118 mmol/L mannitol as an osmolar control (mannitol)]. Levels of VEGF protein in the culture supernatant were measured by ELISA, and mRNA expression was determined by Northern blot analysis. Data are presented as percent of control. RESULTS: After incubation for 4 hours, the number of cells did not differ between the 3 groups. Levels of VEGF in culture supernatant were significantly higher in the HGD group (124% +/- 19%, p = 0.006) as compared with the control and mannitol (85% +/- 10%) groups. The mRNA expression of VEGF appeared to be higher in the HGD group (128% +/- 49%) than in the control and mannitol (94% +/- 18%) groups. CONCLUSION: High glucose dialysis solutions increased VEGF synthesis by PVECs. The relationship between VEGF synthesis by PVECs and neovascularization of the peritoneum observed in long-term peritoneal dialysis patients has to be studied further.

[Correlations of Ki-67 expression and histopathologic characteristics in uveal melanomas].

PURPOSE: To investigate the relations between the cellular proliferation and histopathologic variables in paraffin embedded uveal melanomas with the using of the monoclonal antibody Ki-67 as a proliferation marker. METHODS: Fifty-seven enucleated eyes were included for histopathological study and Ki-67 immunostaining. All these eye globes were enucleated between 1988 and 1997 without prior treatment. RESULTS: The score of Ki-67 index ranged from zero to 4.89%, mean (0.75 +/- 1.02) %. The mean score of Ki-67 was significantly higher in large tumors (P = 0.007) or in tumors that contained epithelioid cells (P = 0.037) when compared to medium size tumors or to spindle cell type tumors. There was a significant difference of the distribution of epithelioid cell and spindle cell when compared histologic cell type with tumor size (chi 2 = 4.528, P < 0.05). Higher proportions of large tumors were found in epithelioid cell group. No significant correlation was found between the Ki-67 index and tumor location, scleral extension and age. CONCLUSION: The Ki-67 index is significantly correlated with the histologic cell type and tumor size.

Optimising dose in peritoneal dialysis (PD).

PD dose is one determinant factor for PD adequacy. With the standard CAPD prescription of 4 x 2 L per day large patients especially after residual renal function has been lost, are at risk of being underdialysed according to the current standards. By using automated PD dialysis dose can be enhanced by individualising prescription and most of even large and anuric patients can be maintained on PD.

Acoustic basis of tuning fork tests.

OBJECTIVES: To obtain pilot data to determine the feasibility of supporting or refuting a theory regarding lateralization of sound in conductive hearing loss and to describe the application of this theory to other tuning fork tests. DESIGN: Controlled audiometric testing with and without a conductive hearing loss. SETTING: A tertiary medical centre. METHODS: Sound pressure levels in external auditory canals were measured during presentation of 40- and 50-dB bone-conducted stimuli. Measurements were taken from five normal male subjects before and after inducing a conductive hearing loss. OUTCOME MEASURES: If sound intensity in the ear canal was greater in the unobstructed ear canal than the obstructed ear canal, the hypothesis was supported. The number of subjects required to provide definitive proof was calculated from the measured intensity difference with and without the conductive loss and the intrasubject variability of sound intensity measurements. The applicability of the theory to other tuning fork tests and auditory phenomena was explored. RESULTS AND CONCLUSIONS: A total of 600 subjects would be required to provide evidence to support our theory using this method. The acoustic impedance mismatch-reflected sound theory could be applied to other tuning fork tests, but until further proof is available, it must be considered only a theory.

Expression of VLA-2, VLA-3, and alpha(v) integrin receptors in uveal melanoma: association with microvascular architecture of the tumour and prognostic value.

BACKGROUND: The interaction of the integrin receptors with their ligands (collagen, laminin, fibronectin, and others) has a crucial role during the reorganisation of the extracellular matrix and the metastatic process. The presence of particular vascular patterns in uveal melanoma is associated with the development of metastases. There is some evidence that interactions between the tumour cells and the extracellular matrix are responsible for the shape of these patterns. METHODS: The expression of VLA-2, VLA-3, and alpha(v) integrin receptors was examined by immunohistochemistry on paraffin embedded tumour specimens from 92 uveal melanomas (iris melanomas excluded). Possible correlations between these results and the tumour vascular patterns, the histological features of the tumours as well as the clinical outcome of the patients, were investigated. RESULTS: The expression of VLA-2 in tumours was associated with the presence of vascular networks (p = 0.05). Tumours with less than 25% VLA-3 positive cells infiltrated the sclera more frequently than those with more than 25% VLA-3 cell positivity (p = 0.05). Tumours expressing less than 50% alpha(v) positive cells were associated with the mixed or epithelioid cell type (p = 0.05) and, with less statistical precision, with the presence of extraocular growth (p = 0.07). The univariate logistic regression analysis showed that the risk of developing metastases within the first 5 years after diagnosis did not depend on the expression of the integrin receptors investigated. CONCLUSION: The potential biological importance of the associations between integrin expression and the histopathological features of the tumours found in the present study remains to be elucidated in future experiments. The immunohistochemical detection of VLA-2, VLA-3, and alpha(v) integrins had no prognostic value in our preliminary report.

The prognostic value of cyclin D1, p53, and MDM2 protein expression in uveal melanoma.

Malignant uveal melanoma is the commonest primary intraocular tumour in adults. It metastasizes frequently and 50% of patients die within 10 years of diagnosis. The expression of cyclin D1, p53, and MDM2 in uveal melanoma and their relationship to metastasis-free 5-year survival was determined, in order to investigate whether these proteins help to distinguish those patients with a favourable prognosis from those with a poorer one. Ninety-six eyes enucleated for uveal melanomas were immunohistochemically analysed for the protein expression of cyclin D1 and related cell-cycle markers, p53 and MDM2. The evaluation of the specimens was undertaken by two independent pathologists without knowledge of the outcome. Statistical analysis of clinical, morphological, and immunohistological features was performed. A 'favourable outcome' was defined as survival of at least 5 years after diagnosis, without metastases (n=57). An 'unfavourable outcome' was defined as death from metastases within the first 5 years after diagnosis of uveal melanoma (n=39). Cyclin D1 positivity (>15% positive tumour cells) as well as p53 positivity (>15% positive tumour cells) was associated with an unfavourable outcome (for cyclin D1: odds ratio=4. 2, 95% confidence interval 1.5-11.8, p=0.006; for p53: odds ratio=3. 2, 95% confidence interval 1.1-9.3, p=0.03). In addition, cyclin D1 positivity was associated with the presence of extraocular extension of the tumour (p=0.01), with the mixed or epithelioid cell type (p=0. 02), and with the tumour cell MIB-1 positivity (p=0.0001). MDM2 immunoreactivity of the tumour cells showed a potential correlation with clinical outcome (odds ratio=2.1, 95% confidence interval 0.8-5. 8, p=0.13). Multiple logistic regression models showed that cyclin D1 positivity is an independent prognostic factor after control for other prognostic markers. The expression of cyclin D1 in uveal melanoma is associated with a more aggressive course and histologically unfavourable disease. This could serve as a further independent prognostic factor in uveal melanoma.

Mutations in the VMD2 gene are associated with juvenile-onset vitelliform macular dystrophy (Best disease) and adult vitelliform macular dystrophy but not age-related macular degeneration.

Recently, the VMD2 gene has been identified as the causative gene in juvenile-onset vitelliform macular dystrophy (Best disease), a central retinopathy primarily characterised by an impaired function of the retinal pigment epithelium. In this study we have further characterised the spectrum of VMD2 mutations in a series of 41 unrelated Best disease patients. Furthermore we expanded our analysis to include 32 unrelated patients with adult vitelliform macular dystrophy (AVMD) and 200 patients with age-related macular degeneration (AMD). Both AVMD and AMD share some phenotypic features with Best disease such as abnormal subretinal accumulation of lipofuscin material, progressive geographic atrophy and choroidal neovascularisation, and may be the consequence of a common pathogenic mechanism. In total, we have identified 23 distinct disease-associated mutations in Best disease and four different mutations in AVMD. Two of the mutations found in the AVMD patients were also seen in Best disease suggesting a considerable overlap in the aetiology of these two disorders. There were no mutations found in the AMD group. In addition, four frequent intragenic polymorphisms did not reveal allelic association of the VMD2 locus with AMD. These data exclude a direct role of VMD2 in the predisposition to AMD.

Expression of the cell adhesion molecules ICAM-1, VCAM-1 and NCAM in uveal melanoma: a clinicopathological study.

To investigate the relationship between the expression of the cell adhesion molecules intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and neural cell adhesion molecule (NCAM) in uveal melanoma and the metastatic spread in the first 5 years after diagnosis, we performed a hospital-based case-control study with human tissue from 90 patients who underwent enucleation for primary uveal melanoma (iris melanoma excluded). Thirty-five patients developed metastasis within the first 5 years, and 55 patients lived metastasis-free for at least 5 years after enucleation. The paraffin-embedded and formalin-fixed globes were studied by immunohistochemistry with monoclonal antibodies for ICAM-1, VCAM-1 and NCAM. A strong ICAM-1 positivity (more than 75% of the tumor cells stained positive) was detected in 73 tumors (81%). The expression of 75% or less ICAM-1 positive cells in tumors was strongly associated with the development of metastases (odds ratio: 7.5, p = 0.001). Multiple logistic regression models showed that ICAM-1 is an independent risk factor for metastasis even after control for important prognostic markers like extraocular growth, ciliary body involvement, scleral infiltration and cell type. VCAM-1 was expressed in 24 out of 88 tumors (27.3%) and NCAM only in 14 out of 87 tumors (16%). Only spindle cells stained positive with anti-NCAM. NCAM and VCAM-1 expression was not related to metastasis. Our results show that the loss of ICAM-1 expression is associated with an increased risk of metastasis within the first 5 years after diagnosis.

First in vitro and in vivo experiences with Stay-Safe Balance, a pH-neutral solution in a dual-chambered bag.

In addition to low pH and high osmolarity, glucose degradation products (GDPs) are considered to play a major role in the bioincompatibility of peritoneal dialysis fluids (PDFs). The formation of GDPs can be reduced by separating the glucose component of the solution (kept at very low pH) from the lactate component of the solution (kept at alkaline pH) during sterilization and storage. This development has been achieved by the use of a dual-chambered bag. Immediately before infusion, the seam between the two chambers is opened, and the contents are mixed. The result is a fluid with a more physiologic pH in the range 6.8 - 7.4. Concentrations of 3-deoxyglucosone (3-DG), methylglyoxal (MG), acetaldehyde (AA), and formaldehyde (FA) in Stay-Safe Balance (Fresenius Medical Care, Bad Homburg, Germany) were remarkably reduced when compared to conventional PD solution [conventional PDF (1.5% glucose): 172 micromol/L, 6 microLmol/L, 152 micromol/L, and 7 micromol/L respectively; Stay-Safe Balance (1.5% glucose): 42 micromolL, < 1 micromol/L, < 2 micromol/L, and < 3 micromol/L respectively; conventional PDF (4.25% glucose): 324 micromol/L, 10 micromol/L, 182 micromol/L, and 13 micromol/L respectively; Stay-Safe Balance (4.25% glucose): 60 micromol/L, < 1 micromol/L, < 2 micromol/L, and < 3 micromol/L respectively). Human peritoneal mesothelial cells (HPMCs) were exposed to a control solution, a conventional PDF [CAPD 2, 1.5% glucose (Fresenius Medical Care, Bad Homburg, Germany)], and Stay-Safe Balance, either in a co-incubation model (24-hour PDF exposure) or in a pre-incubation model (30-min PDF exposure), followed by 24-hour recovery in culture medium. Interleukin-1beta (IL-1beta)-stimulated (1 ng/mL) IL-6 secretion from HPMCs was assessed by ELISA. Exposure of HPMCs to conventional PDF resulted in a significant reduction in IL-6 release, which was fully restored following exposure to Stay-Safe Balance. In addition to the short-term investigations, long-term in vitro studies were also carried out. All fluids had near-neutral pH and were changed every second day. After 1, 3, 5, 7, 10, and 13 days of exposure, cell viability was assessed. Whereas exposure to conventional PDF resulted in a significant reduction in HPMC viability after just 3 - 5 days, no significant toxicity of filter-sterilized or dual-chambered fluid was observed for up to 13 days. An observational study with 9 patients suggested that the efficacy of Stay-Safe Balance is equivalent to that of conventional solution. However, even short-term treatment (8+/-1 weeks) with this more biocompatible solution seems to improve mesothelial cell mass as indicated by a rise in cancer antigen 125 (CA125) from a baseline of 47+/-37 U/min to 172+/-90 U/min. Our data indicate that Stay-Safe Balance may help to better preserve peritoneal membrane cell function. An ongoing European multicenter study is expected to confirm these results.

Continuous ambulatory peritoneal dialysis in high-risk patients: patients with cardiovascular diseases--role of the nurse.

Most patients receiving renal replacement therapy have cardiovascular disease. The most frequent conditions are left ventricular hypertrophy and coronary artery disease. Hemodialysis is associated with a characteristic spectrum of acute complications (such as hypotension, sudden death) that can be explained by typical dialysis-induced effects on the heart. With continuous peritoneal dialysis (CAPD) some of the cardiovascular complications are ameliorated owing to slow ultrafiltration and absence of an arteriovenous fistula. CAPD might be concluded to be the preferable option in patients with cardiovascular disease, but a few disadvantages, such as hyperlipidemia and hyperinsulinemia, also exist. Nurses also play an important role in the therapeutic success and outcomes of these patients.