Mechanisms of enhanced carbohydrate and lipid metabolism in adipose tissue in uremia.

OBJECTIVE: Hyperlipidemia is a permanent finding in advanced renal failure. It is supposed to be responsible for the accelerated arteriosclerosis and cardiovascular complications observed in patients with that disease. The background is partially determined, however, our knowledge in this matter is not yet satisfactory. METHODS: This study is based on the experimental rat model of chronic renal failure (CRF). Considering white adipose tissue (WAT) lipogenesis upregulation in CRF, along with the determination of acetyl coenzyme A carboxylase (ACC) and fatty acid synthase (FAS) genes expression, we have measured WAT gene expression for sterol regulatory binding protein 1 (SREBP-1) at the level of protein mass and mRNA abundance. Furthermore, we have determined glucose uptake, glucose-to-CO 2 conversion rate, and glucose translocator (GLUT-4) gene expression in WAT. RESULTS: Upregulation of both FAS and ACC gene expression was found in WAT of CRF rats. It was accompanied by WAT SREBP-1 gene overexpression. Moreover, we have observed the increased glucose uptake, glucose to CO 2 conversion rate, and GLUT-4 gene expression in WAT of CRF rats in comparison with controls. CONCLUSION: SREBP-1 gene overexpression may contribute to enhanced lipogenesis upregulation in WAT of CRF rats. It is not excluded that the increased WAT glucose metabolism activity is also induced by this mechanism, although there is no evidence currently to that end. We hypothesize that the increased WAT lipogenesis capacity could be a part of mechanism(s) leading to CRF-induced hyperlipidemia.     

The influence of erythropoietin on cytokines in haemodialysis patients

Summary: In this study, the administration of erythropoietin to haemodialysis patients revealed its immunomodulating properties. to dissociate the immunological effects of erythropoietin action from its haematological effects the patients in our study were administered recombinant human erythropoietin (rhEpo) at the doses that would not affect erythropoiesis. After baseline data had been obtained, six haemodialysis patients were given rhEpo (Eprex-Cilag) at the dose 7-10 U/kg bodyweight/s.c., three times a week, for 12 weeks. All patients maintained a stable haemoglobin concentration; no blood transfusions were required. Serum levels of tumour necrosis factor (TNF), IL-2 and IL-6 levels of the study patients and the four control patients, not receiving rhEpo, were monitored every 2 weeks. the levels of IL-6 and TNF remained unchanged; however, a low serum level of IL-2, recorded before therapy, increased gradually for 10 weeks until it reached the values observed in normal healthy humans (P<0.01). After that it dropped to the initial values. During the study the red blood cell numbers did not change. This study supports the thesis that erythropoietin administered to haemodialysis patients not only corrects anaemia but also independently modulates immunological response.     

Primitive Cerebral Tumor with Rhabdoid Features: A Case of Phenotypic Rhabdoid Tumor of the Central Nervous System

The rhabdoid tumor (RT) was first described as an aggressive neoplasm of unknown histogenesis affecting the kidneys of infants and young children, but has since been reported in all ages and in many other primary sites, including the central nervous system. It has been shown, however, that the histologic and cytologic features of RT can be mimicked by many other tumors of known histogenesis. For this and other reasons it remains controversial whether cases of putative extrarenal RT represent the same histogenetic entity as RT of the kidney (RTK), another entity or entities, or merely a diverse collection of unrelated tumors sharing a common morphologic phenotype. The present paper describes a lethal primary cerebral tumor in a 26-month-old Hispanic boy that was composed predominantly of cells exhibiting the “classic” rhabdoid phenotype by light microscopy. lmmunocytochemical and ultrastructural studies disclosed features of primitive neuroglial differentiation not seen in RTK. The findings in this case, as well as evidence from other studies, would seem to support the notion that primary RT of the brain may in fact constitute a morphologic and clinicopathologic entity. However, hat entity likely represents a distinctive type of neuroglial neoplasm, more closely related t o other primitive brain tumors than t o RTK.     

Renal anaemia treatment in haemodialysis patients in the Central and Eastern European countries in everyday clinical practice follow-up

Background

Chronic kidney disease is almost always accompanied by anaemia. Erythropoietin-stimulating agents (ESA) can increase haemoglobin concentration and thus reduce the frequency of anaemia-related complications including the cardiovascular events.

Aim

The aim of the study was to collect prospective data on 12-month standard ESA therapy used in haemodialyzed patients in selected CEE countries as well as on cardiovascular complications, iron status and anaemia treatment.

Patients and methods

Fifty centres in 3 countries participated in the study. A group of 398 haemodialysed stable patients (M-231, F-167) aged 19–90 years (57.5 ± 14.7) on standard ESA therapy for chronic renal anaemia were recruited. Twelve-month prospective data on iron parameters, ESA therapy and cardiovascular events were collected. The use of iron, folic acid and blood transfusions were also assessed. Patient were divided into three groups according to ESA therapy start: group A—patients who received ESA after start of haemodialysis, group B—patients who received ESA within 3 months from the day of first haemodialysis and group C—patients who had received ESA more than 3 months before haemodialysis. Chi² test for qualitative data and Kruskall–Wallis test for quantitative data with p < 0.05 were used in statistical analysis.

Results

At prestudy period, the mean weekly dose of ESA in group C was statistically lower than in the remaining two groups (3,823 ± 3,169 vs. 5,276 ± 2,915 and 6,427 ± 3,441 units/week, p < 0.001), but during prospective phase of the study the doses did not differ among groups A, B and C. No major fluctuation of ESA administration schedule was observed during the study in the groups; however, at majority of visits, the mean frequency of ESA administration in group C was statistically higher than in groups A and B. At baseline visit, the haemoglobin concentration in group A patients (10.86 ± 1.34 g/dL) was slightly lower than in group B (11.26 ± 1.43 g/dL) and group C (10.98 ± 1.35 g/dL) (p = 0.025), but at subsequent visits these differences disappeared and mean haemoglobin concentration was stable around 11 g/dL. Ferritin concentration increased from 280 ± 241 at baseline to 506 ± 405 at month 12, and no important differences in the groups were observed. The other haematological parameters (haematocrit, iron concentration) remained stable during the entire study. The frequency of blood transfusion and total volume of blood in group C were lower than in groups A and B. During the prospective 12-month follow-up, 23 (5.8 %) of the patients died and 35 (8.8 %) were transplanted. No differences in death or transplantation rate were observed among groups A, B and C. The number of patients with adverse events, serious adverse events or drug-related adverse events in all groups was similar. In conclusion, ESA therapy increased haemoglobin concentration and no major differences in haematological parameters among the groups were observed during the entire study irrespective of early versus late start. Mortality, cardiovascular events or other adverse events were similar among the groups during the observation period; however, the limitation of the study is the sample size.     

Inflammatory infratentorial progressive multifocal leukoencephalopathy in a patient with rheumatoid arthritis

An 84–year‐old man with rheumatoid arthritis (RA) treated with methotrexate, developed progressive confusion and cerebellar symptoms, and died approximately 2 months later. Neuropathological examination revealed progressive multifocal leukoencephalopathy (PML) involving the cerebellum and brainstem. The affected tissues displayed intense infiltrations by CD8+ T‐cells and microglia. JC virus was localized in oligodendroglia and cerebellar granule cells. This case illustrates unusual localization of inflammatory PML in a patient with RA treated with methotrexate.     

High plasma adenine concentration in chronic renal failure and its relation to erythrocyte ATP

BACKGROUND: Concentration of plasma adenine has been found to increase in chronic renal failure (CRF). The aim of the present study was to evaluate whether high plasma adenine concentration contributes to the elevated ATP in erythrocytes of patients with CRF. METHODS: Three groups of patients with CRF were studied: (A) 30 patients with different degree of CRF; (B) 11 patients on hemodialysis, and (C) 12 patients after successful renal transplantation. Concentrations of plasma adenine and erythrocyte adenine nucleotides were measured in groups A, B and C. Furthermore, adenine incorporation into erythrocyte adenine nucleotide pool was measured in group A. RESULTS: A positive correlation between plasma adenine and creatinine concentrations was found in CRF as well as between plasma adenine and erythrocyte ATP. Furthermore, positive correlation was evident between the rate of adenine incorporation into erythrocyte adenine nucleotide pool and the severity of CRF. A significant reduction in both plasma adenine and erythrocyte ATP was observed immediately following hemodalysis, but 2 days later, high predialysis plasma adenine and erythrocyte ATP concentrations were restored. Following successful renal transplantation erythrocyte ATP and plasma adenine concentrations reached control values. CONCLUSION: Our results provide evidence that plasma adenine concentration increases in parallel to the progress of the disease and that it could be responsible for the increase in erythrocyte ATP of patients with CRF.