Positive effect of oral supplementation with glycosaminoglycans and antioxidants on the regeneration of osteochondral defects in the knee joint

The effect of oral supplementation with glycosaminoglycans (GAG) and radical scavengers (vitamin E/selenium) on the regeneration of osteochondral defects was investigated in rabbits. After introduction of defined osteochondral defects in the knee joint, groups of ten animals were given a GAG/vitamin E/selenium mixture or a placebo (milk sugar) for 6 weeks. Following sacrifice, histological and histochemical analysis was performed. The amount of synovial fluid was increased in the placebo group, while the viscosity of the synovial fluid was significantly enhanced in the GAG group. The amount of sulfated GAG in the osteochondral regenerates (8.8 +/- 3.6 % vs. 6.0 +/- 5.6 %; p <0.03) was significantly higher in the GAG group. In both groups, the GAG amount in the cartilage of the operated knee was significantly higher than in the non-involved knee (p <0.05). Histological analysis of the regenerates in the GAG group was superior in comparison with the placebo group. For the first time, a biological effect following oral supplementation with GAG was demonstrated in healing of osteochondral defects in vivo. These findings support the known positive clinical results.

[Analysis and adjustment of acid-base disturbances according to the Stewart-Fencl principle]

In 1983, P. J. Stewart proposed a new approach for evaluation of acid-base balance of body fluids. He defined three independent variables responsible for hydrogen ion concentration in body fluids: 1. the partial pressure of carbon dioxide (pCO2); 2. strong ion difference, SID, i.e. the difference between the sums of all the strong (fully dissociated, chemically nonreacting) cations and sums of the strong anions; 3. the total concentration of all the non-volatile weak acids (mainly albumin) designated as [Atot]. On the basis of this theory, V. Fencl invented a new classification of clinical acid-base disturbances. Respiratory acidosis and alkalosis result from abnormalities of pCO2. The classifications of the respiratory disturbances of ABR is identical as in the conventional viewing which is based on the dissociation equation of carbonic acid. Metabolic acidoses or alkaloses result from derangements of the SID and/or [Atot]. The change of SID value is a consequence of either dehydration (alkalosis) or hyperhydration (acidosis). Other mechanisms of SID deviation are either changes of serum chloride concentration (an increase causes acidosis, a decrease causes alkalosis) or an increase of concentrations of substances not routinely measured (ketones, lactate, exogenous acids). [Atot] value is determined mainly by the serum albumin concentration (alkalosis in hypoalbuminemia, acidosis in hyperproteinemia). The Stewart-Fencl approach to acid-base balance enables to understand and predict what happens to hydrogen ions in body fluids and to control the pH abnormalities quantitatively.

[IgA nephropathy. Use of modern laboratory methods and renal biopsy for diagnosis]

IgA nephropathy is the most frequent primary glomerulonephritis worldwide. At its onset, the most common laboratory sign is isolated haematuria often accompanied with mild proteinuria (up to 1.5 g/24 h). The disease displays a progressive course with end-stage renal disease occurring in up to half of patients 20 years after onset. Diagnosis is established by immunofluorescent microscopy of a renal biopsy specimen. Discoveries in the past decade on the pathogenesis of IgA nephropathy together with complex evaluation of its clinical presentation enable to establish diagnosis with a satisfactory degree of probability even without biopsy. IgA nephropathy patients display increased or borderline serum IgA levels; increased serum levels of IgA fraction with degalactosylated O-linked side sugar chains; increased serum levels of anti-N-acetylgalactosamine antibodies; increased levels of circulating immune complexes composed of IgA1 complexed with IgG or IgA1; increased serum levels of circulating complexes composed of IgA and fibronectin; and frequent occurrence of the rheumatoid IgA factor. Clinical use of these still generally unavailable methods would reduce the renal biopsy indication in patients with isolated or predominant haematuria.

[Postural trauma and rhabdomyolosis causing acute renal failure]

Rhabdomyolysis (damage of the muscles of various origin) leads to the efflux of the intracellular fluids in the circulation. The common complication of this status is the renal failure. The early diagnosis and the proper treatment makes the fall of renal function reversible. That is why the possibility of the rhabdomyolysis must be consider. The case report describes the development of renal failure in young, previously healthy men, followed by trauma mechanism after drug and alcohol abuse.

Long-term control of hypertension and the predictive value of peripheral plasma renin activity after ablation of end stage kidneys with a new embolic agent

Embolization of end-stage kidneys using our own embolizing agent Vilanol (partially hydrolyzed polyvinyl acetate) was performed in 10 patients with hypertension refractory to conservative therapy. Native kidneys were embolized in 7 patients with chronic renal failure, nonfunctioning renal transplants in 2 patients, and a shrunken kidney in 1 patient. Five of the 10 patients had high (9.96-18.2 ng/ml/h) peripheral renin (PR) levels. The embolization was technically successful in 4 of these 5 patients and was immediately followed by a marked decrease in PR, and simultaneous improvement in blood pressure (BP). The other 5 patients had very low PR levels (0.07-0.65 ng/ml/h), and a reduction in BP was observed in 4 after embolization. One patient died following embolization from cardiac arrest due to hyperkalemia. Six patients (3 in each group) have been on follow-up for 2-5 years with sustained decrease in BP. We conclude that the new agent is effective for renal ablation and control of refractory hypertension.

[Effectiveness of replacement of renal function in diabetics]

The authors compared the survival of four groups of patients and of renal grafts: 1. diabetics after renal transplantation (24 subjects), 2. diabetics after transplantation of the kidney and pancreas (35 subjects), 3. diabetics where transplantation was indicated but who were treated only by dialysis and 4. non-diabetics after transplantation of the kidney (170 subjects). The two-year cumulative survival of the entire group of diabetics regardless of the type of treatment was 59%. The two-year survival of diabetics after transplantation of the kidney alone was 95%, after transplantation of the kidney and pancreas 70% and in non-diabetics after transplantation of the kidney 90%. In diabetics treated by dialysis it was 33%. The two-year survival of the function of renal grafts in the entire group of diabetics treated by transplantation of the kidney was 61%, in non-diabetics 68% and the three-year survival was in both groups 61%. As compared with the EDTA register, the results of transplantation treatment are favourable, the results of dialyzation treatment are poor. From the results the authors draw conclusions for indication of different ways of replacement of renal function in diabetics in relation to the general health status of the patients.

Spironolactones and glomerular filtration

For pharmacologic screening to identify hyperaldosteronism in patients after renal transplantation, spironolactone (Soludactone, Searle) was administered intravenously in 12 subjects (mean dose 1.2 g in the course of 3 days). After its administration a decrease in glomerular filtration rate was assessed when measured by chromogen clearance. Simultaneous measurement of creatinine showed no change, nor was there any change in the plasma level and excretion fraction of urea. The decrease in chromogen clearance was due to an increase in plasma level of the chromogen. Thus the decrease in its clearance was an artifact resulting most probably from the reaction of spironolactone metabolites with alkaline picrate, which was used for the determination of chromogen. In addition to the causes of the glomerular filtration rate decrease after spironolactone which have been reported in the literature - volume depletion and direct influence on the kidneys - the possibility of a fictive decrease must be taken into consideration.

Acute effect of furosemide on Na and K excretion fractions in patients with allotransplanted kidney

The acute effect of 20 mg i. v. furosemide on the excretion fraction (EF) of osm, Na, K, and urea was investigated in groups of 32 patients with chronic renal disease and 20 with renal allograft. In renal patients furosemide elicited comparably high increment (delta) of EF osm, Na, and K in both the stage of renal insufficiency and at normal Cin. In transplant patients, the delta EFosm increased in linear relationship to increasing Cin. The different response seems to be attributable to the significance of the correlation of delta EFk to delta EFosm, resp., delta EFNa. The results indicate that in transplant patients the acute effect of furosemide on tubular transport of solutes increases with increasing GFR. This finding could be explained by the influence on potassium excretion.