Chronic renal insufficiency: 1) adaptation of nephron function in chronic renal insufficiency and 2) progression of chronic renal insufficiency

In chronic renal insufficiency resulting from destruction of the vast majority of nephrons, the surviving nephrons adapt their functions to the conditions of vigorous haemodynamic and osmolar overloads. They acquire an appropriate behaviour to preserve the principal renal functions and to achieve the balance of inner space. In the long period of time, similarly as in healthy people. Glomerulotubular balance as well as tubuloglomerular balance distinguish the remaining nephron function, while autoregulation of perfusion pressure along the glomerulus rapidly vanishes. All three regulation mechanisms are characteristic of the nephron function under physiologic conditions. Intense work of the remaining nephrons in chronic renal failure is under the high level controls of the group of hormones, among them are rennin-angiotensin system, arginine-vasopressin and atrial natriuretic peptide playing very important and particular roles. Comparison of different published studies emerge the idea that chronically increased arginine-vasopressin levels in chronic renal failure could block the autoregulation of blood flow and hydraulic pressure in glomeruli, which together with other mediator actions give high and fluctuating tense within remaining glomeruli, during every single cardiac cycle. It is probably the main event in the further course of kidney disease progression resulting in definite damage of the overloaded nephrons. Angiotensin II is one of reliably recognised mediators of unfavourable outcome in the process of nephron adaptation in chronic renal failure. Knowing the pathophysiologic processes in the remaining functionally adapted nephrons in chronic renal insufficiency determines a more adequate therapeutic approach in these patients.     

Pericarditis in chronic compensated renal insufficiency

In 80 patients with renal insufficiency we found 15 cases of pericarditis, demonstrated by the diagnostic means of echocardiography. The incidence of pericarditis increased with the rise in serum-creatinin and the severity of hypalbuminemia. These findings confirm the assumption that toxic capillary damage combined with lowered oncotic pressure might be a cause of pericardial effusion. Echocardiography as a reliable and non-invasive diagnostic method should be applied routinely in patients with chronic renal insufficiency--regarding potential therapeutic consequences--especially in patients with a concomitant incidence of hypalbuminemia and pleural effusion.     

Treatment of urinary infections in chronic renal insufficiency

The author describes some differences in the course of treatment of urinary pathway infections in prolonged reduced renal function. He emphasizes changes from the aspect of the clinical course of urinary infections and changes in the pharmacokinetics and pharmacodynamics of antibiotics and principles for selection of therapy are outlined.     

Cognitive disorders in patients with chronic renal insufficiency

Papillomaviruses are pathogens which induce cutaneous and mucosal lesions in man and in many animal species. The characterization of these viruses was rather low, because viral infection cannot be fully reproduced in cell culture. The development of molecular biology techniques in the 1970s permitted to establish the remarkable plurality of the viruses, the tissue specificity and pecular pathogenicity linked to the type. Studies of the genome organization, the gene expression regulation and the protein characterization gave many informations leading to understand the mechanisms of viral-related carcinogenesis, especially the role of HPV16, the major risk factor for the development of squamous cervical carcinoma.     

Histamine-stimulated gastric secretion in rats with chronic renal insufficiency

Chronic uremia was induced by long-term maintenance of rats which had undergone sub-total nephrectomy, with sham-operated rats serving as controls. Chronic gastric cannulas and chronic vascular catheters (vena cava) were installed and the rats were stimulated with intravenous infusion of histamine. In uremic rats, the volume of gastric juice, output of HC1 and H+ concentration were significantly higher than in the controls during the 6-hour secretion experiments.     

Progression of chronic renal insufficiency in chronic rejection: the role of chronic transplantation glomerulopathy

The authors studied variations in the pulsatility index of the uterine arteries in postmenopausal women who had received hormone replacement treatment (HRT) for at least one year and compared them to those in a control group not receiving HRT. The results showed a significant variation in this index with the tendency to assume lower values compared to the control group, thus resulting in increased uterine vascularization, almost resembling that observed during the child-bearing period. This drop in the pulsatility index should probably be considered the anatomo-functional in patients not receiving HRT.     

Acute renal insufficiency in renal transplants treated with interferon-alpha for chronic hepatitis C

Small-angle x-ray scattering (SAXS) can provide information on mean size, predominant orientation and typical shape of mineral crystals in bone. In this paper, recent developments of this technique for application in bone research are reviewed. Then the structure of the collagen/mineral composite in bone, as determined by SAXS, is compared for a number of species. The thickness of the mineral crystals was found to increase with age up to a value around 3 to 4 nanometers in adult animals, depending on the species. The SAXS results also suggest the existence of needle-shaped mineral crystals in mouse or rat bone and more plate-shaped crystals in other tissues like adult human bone or mineralized turkey leg tendon.