Search PubMed⌕ Search

Biomedical subjects

Petar Kes

Publications and source records attributed to Petar Kes.

11 recordsLinked to original sources
PubMed2003

The role of arterial hypertension in the progression of non-diabetic glomerular diseases.

Arterial hypertension (AH) per se is, together with diabetes mellitus, the most important cause of renal failure and of dialysis in the western world. AH is also a well known consequence of chronic renal disease, and at the same time one of the main factors which causes diabetic and/or non-diabetic chronic renal failure progression. AH is mostly registered in patients with focal segmental glomerulosclerosis and with membranoproliferative glomerulonephritis. The pathophysiology and the mechanism of AH within primary glomerular diseases are complex, including activation of the sympathetic nervous system, the renin-angiotensin system (RAS), sodium retention, volume expansion and decreased synthesis of vasodilatatory substances. As autoregulation of glomerular pressure in chronic glomerular disease is disturbed, the increment in systemic blood pressure leads to the rise in glomerular pressure. Glomerular hypertension results in glomerular capillary wall stretch, endothelial damage and a rise in protein glomerular filtration. These processes, in turn, cause changes of mesangial and proximal tubular cells, ultimately resulting in the replacement of functional by non-functional connective tissue and the development of fibrosis. One of the most important factors in the progression of chronic renal failure is activation of the RAS. Its effect is not only elevated blood pressure, but also the promotion of cell proliferation, inflammation and matrix accumulation. Many studies, first in experimental animals and later in humans, have shown that the lowering of blood pressure (and proteinuria) is associated with a slower progression of kidney disease. It seems that angiotensin-converting enzyme inhibitors (ACEIs) are more renoprotective than other antihypertensives (the protection beyond the antihypertensive effect), although some studies have also confirmed a comparatively beneficial effect of non-dihydropiridine calcium channel blockers (CCBs) and angiotensin II receptor blockers (ARBs). Moreover, it seems that a combination of antihypertensives (e.g. ACEI + CCB, ACEI + ARB) has a more effective action than either of the drugs alone. However, the effects depend first on the degree of blood pressure reduction. According to comprehensive studies, the achievement of adequate blood pressure (not higher than 130/85 mmHg) is the most important factor. An even lower blood pressure (125/75 mmHg) has been suggested as the limit value in patients with proteinuria of >1 g/24 h and in Blacks.

Aged↗
PubMed2003

[Long-term monitoring of children with focal segmental glomerulosclerosis and a transplanted kidney].

INTRODUCTION: Focal segmental glomerulosclerosis (FSGS) is an important cause of nephrotic syndrome and end-stage renal disease. Children with FSGS are at a risk of recurrence of disease following renal transplantation. The rate of recurrence has been estimated to range from 15% to 50%, having a potentially detrimental course towards the loss of renal function. The factors associated with an increased probability of recurrence are not well known. PATIENTS: The authors followed 8 pediatric patients (3 girls and 5 boys) with FSGS who had undergone renal transplantation (16% of all transplanted pediatric patients) over a long period (1982-2001). The mean age of the children at the time of disease onset was 4 years and 8 months (range: 2 months-12 years). Children were monitored from 10 months to 4 years before the first dialysis. On average, the first dialysis was performed at 7 years of age (range: 12 months-16 years). Time elapsed between the first dialysis and transplantation ranged from 1 to 3 years (mean 1.5 year), and mean age at transplantation was 8 years and 6 months (range: 4-18 years). The grafts were from 2 living-related and 6 cadaveric donors. Five recipients were immunosuppressed with cyclosporin A (CsA) -steroids-azathioprine (Aza), 2 with CsA-steroids-mycophenolate mofetil (MMF), and 1 with CsA-steroids regimen. Follow-up period after transplantation ranged from 2 to 15 years (mean time 7 years and 8 months). RESULTS: Creatinine values, proteinuria range and blood pressure were monitored every 3 months after transplantation, and were as follows: creatinine 41-386 mumol/l (mean value 153 mumol/l), proteinuria 0.01-3,14 g/l (mean 0.27 g/l, median 0.03 g/l), systolic blood pressure 90-140 mm Hg (mean 110 mm Hg), diastolic blood pressure 60-90 mm Hg (mean 80 mm Hg). Two patients developed hypertension grade I and III after renal transplantation. There were 5 (0.6 per patient) acute rejection episodes. Two grafts (25%) were rejected 5 and 9 years after transplantation, but recurrence of FSGS was not confirmed by renal biopsy. CONCLUSION: Due to the small sample size no firm conclusions about recurrence of FSGS could be made. However, the fact that none of 8 children developed recurrence of FSGS after renal transplantation speaks against the relatively high recurrence rates in our pediatric population.

Adolescent↗
PubMed2003

[Indications for continuous renal function replacement therapy].

One of the most important achievements in the contemporary intensive care management is introduction of continuous renal replacement therapy (CRRT). The most common indications for CRRT are acute renal failure complicated with heart failure, volume overload, hypercatabolism, acute or chronic liver failure, and/or brain swelling. Less common indications include systemic inflammatory response (SIRS), sepsis, multiorgan failure (MOF), adult respiratory distress syndrome, crush syndrome, tumor lysis syndrome, lactacidosis, and chronic heart failure. Methods of CRRT could be used during or after open heart operations, heart, lung or/and liver transplantation in adults and children. Modern approach to treatment of acute renal failure introduces dialysis early in the course of disease in order to avoid complications on other organs. Sepsis, SIRS and septic shock are still major therapeutic problems in intensive care units with a mortality rate over 50%. Numerous uncontrolled and several controlled clinical studies have demonstrated that CRRT could remove inflammatory substances including cytokines, activated components of the complement, and derivatives of the arachidonic acid. Hemodynamic stability and gas exchange in the lungs were significantly improved. These is due not only to removal of inflammatory substances but also to other nonspecific hemodynamic effects (control of body temperature, fluid and metabolic balance). Besides the convection, cytokines could be removed from the plasma with adsorption on the membrane of dialyzer or hemofilter. Prophylactic use of CCRT in patients with normal renal function, without disturbances in fluid excretion and with normal hemodynamics is still controversial, while the possible benefit is not higher than the risks of invasive therapeutic method, and there is no evidence that prophylactic CCRT could prevent development of acute renal failure in these patients. However, current knowledge of MOF pathophysiology justifies the use of CRRT in patients with signs of heart failure, disturbances in metabolic and fluid homeostasis and sepsis, and in patients with the risk of developing acute respiratory failure or MOF, despite the mild impairment of renal function according to laboratory results.

Humans↗
PubMed2003

[Primary cytomegalovirus infection after combined cadaveric transplantation of the liver and kidney].

Seronegative transplant recipients are at a high risk of developing primary cytomegalovirus (CMV) infection. The D+/R--constellation produces a 60%-80% probability of CMV disease. In such cases CMV prophylaxis is justified. Presentation of a 12-year old boy who developed a primary CMV infection following A combined liver-kidney transplantation; evaluation of prophylactic options and review of some difficulties in the diagnosis of CMV infection. A cadaveric liver-kidney transplantation (Tx) was done in a 12-year old boy with ESRD due to type I primary hyperoxaluria. CMV status: D+, R-; number of mismatches: 5. PRA 0; kidney cold ischemia time (CIT): 13.54 h; liver CIT: 10.10 h; immediate diuresis; Immunosuppression protocol: anti IL-2 receptor antibodies, steroids, mycophenolate mofetil (MMF); cyclosporine introduced on day 6. Over the first week, daily hemodialyses were done in order to remove oxalate deposits. Kidney and liver biopsies: no ACR, no oxalate deposits. CMV prophylaxis with ganciclovir started on day 0. Routine serology and PCR for CMV follow-up showed: pp 65, IgM and IgG, CMV. DNA (Murex CMV. DNA Hybrid Capture test 2.0): negative over the first 3 months. Day 98: CMV pp 65 positive, IgM neg, DNA neg. Day 108: pp 65 neg, IgM positive, IgG neg. CMV. DNA positive (15 x 105 copies/ml). Clinical status: except for mild Cushing, liver tests and kidney function were normal. Ganciclovir was administered intravenously (i.v.) and after 14 days continued perorally. A few days later, leukopenia with severe neutropenia (neutrophil count: 400) and right otitis media developed. MMF and ganciclovir were withdrawn for a few days and reintroduced after WBC count reconstitution. We had no possibility to monitor MMF. Day 150 pp 65 neg, IgM still positive, IgG neg. No clinical signs of infection. Liver and kidney functions normal. After liver-kidney transplantation in a CMV high-risk pediatric patient (D+/R-), asymptomatic CMV primary infection developed. Although ganciclovir prophylaxis could not prevent the infection, it was mild and delayed. Due to bone marrow suppression, discontinuation of MMF and ganciclovir was necessary. Antigenemia assay pp 65 did not correlate very well with CMV viremia so it could not be recommended as a routine test. It should be used in combination with other CMV tests.

Child↗
PubMed2002

[Effect of erythropoietin therapy on serum lipoprotein levels in patients on hemodialysis].

Disturbed lipoprotein metabolism is a well-documented feature in hemodialysis (HD) patients, and lipoprotein disturbances have been clearly linked to premature cardiovascular disease. The aim of this prospective study was to evaluate whether recombinant human erythropoietin (rHuEpo) therapy affects lipid metabolism. The study was performed in 40 chronic HD patients treated for three years with rHuEpo subcutaneously at the end of each dialysis session. Target hemoglobin (Hb) was 110 g/L. The control group consisted of 20 matched HD patients not treated with rHuEpo. Total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoprotein A1 and B as well as lipoprotein (a) were assessed at baseline (without rHuEpo) and at months 6, 12, 18, 24, 30 and 36. In rHuEpo treated group a significant decrease in total cholesterol (6.05 +/- 1.0 vs. 5.15 +/- 0.6 mmol/L; p < 0.05), LDL-cholesterol (3.5 +/- 0.5 vs. 3.08 +/- 0.4 mmol/L; p < 0.05), apoprotein B (1.17 +/- 0.07 vs. 1.12 +/- 0.06 g/L; p < 0.05) and serum triglycerides (2.37 +/- 0.6 vs. 2.0 +/- 0.4 mmol/L; p < 0.05) and a significant increase in HDL-cholesterol (0.88 +/- 0.2 vs. 1.08 +/- 0.2 mmol/L; p < 0.05) occurred during the study. The improvement in each of the lipid parameters correlated significantly (p < 0.05) with the increase in Hb. It could be concluded that long-term rHuEpo treatment is associated with an improvement in the lipid profile. These results suggest that the high incidence of cardiovascular diseases in HD patients might be reduced with rHuEpo therapy.

Adult↗
PubMed2002

[Neurologic sequelae of bone changes in multiple myeloma and its therapy].

Multiple myeloma (MM) is a plasma cell malignancy characterized by infiltration of bone marrow, bone destruction, infiltration of soft tissues with plasma cells, and suppression of normal hematopoiesis. The production of monoclonal immunoglobulins with or without light chains is a major feature of the disease. Full spectrum of plasma cell dyscrasias include monoclonal gammapathy of undetermined significance, smouldering myeloma, indolent multiple myeloma, and fully developed, symptomatic multiple myeloma. The usual presenting features of MM include bone pain, weakness, fatigue, fever and infection. Neurologic symptoms are less common but one must not forget that MM may present with a neurologic disease. Careful neurologic history and examination are mandatory in patients with MM. Neurologic symptoms may be a direct manifestation of MM or may be due to the immune effect of monoclonal proteins directed against different neural structures. Finally, metabolic consequences (uremia, hypercalcemia, hyperviscosity) of MM may produce a broad spectrum of different neurologic symptoms including headache, blurring of vision, drowsiness, precoma, coma, vertigo, ataxia, hemiparesis and epileptiform seizures. The most common location of bone changes in MM is the thoracic spine, where it causes osteolytic changes with consequent compressive fractures. The most disastrous sequel is paraplegia. Multiple vertebral involvement with the evidence of osteolytic changes in other bones is usual, but solitary vertebral myeloma may occur. Myeloma usually involves the bone of the vertebral body and then spreads into the extradural space. However, patients with solitary extradural myeloma have been reported. Skull myeloma is frequently asymptomatic. It may grow externally or, rarely, there is intracranial expansion. Involvement of the cranial nerves is not rare, with II, V, VI, VII and VIII cranial nerves being most often affected. Isolated intracerebral plasmacytomas are extremely rare. Diagnostic approach includes plain X-rays of the skeleton, which was found to be the method of choice for demonstration of osteolytic changes, whereas magnetic resonance with gadolinium enhancement most reliably displays the degree of vertebral involvement and demonstrates any associated soft tissue mass. Current treatment of osteolytic changes in multiple myeloma include chemotherapy, radiotherapy in combination with dexamethasone, monthly infusions of bisphosphonates, surgical decompression, and kyphoplasty. Therapeutic approach is dictated by the presenting symptoms. In case of pain as the predominant symptom, treatment with chemotherapy and radiotherapy may be appropriate. Compressive symptoms are relieved with dexamethasone followed by radiotherapy and chemotherapy. Surgical decompression is used in patients with vertebral collapse and vertebral instability. Kyphoplasty is a new method used in the treatment of osteolytic changes of vertebral bodies. A viscous cement is injected into the cavity by a balloon-like inflatable bone tampon. It has been successfully employed to improve the quality of life, to reduce pain, and to increase overall functioning in patients with vertebral compression fractures by restoring most of the original height of the vertebral body. Bisphosphonates reduce pain associated with osteolytic changes in multiple myeloma, but also significantly reduce skeletal events (pathologic fracture, spinal cord compression, surgery or irradiation of bone) via unknown mechanism. It seems that bisphosphonates, by inhibiting bone resorption, alter the microenvironment in which the MM cells grow.

Central Nervous System Diseases↗
PubMedDate not supplied

[Lipoprotein disorders in chronic kidney failure, nephrotic syndrome and dialysis].

Cardiovascular, cerebrovascular and peripheral vascular diseases are the largest cause-specific reason for morbidity and mortality in end-stage renal disease (ESRD) patients. High prevalence of cardio- and cerebrovascular death may be explained by multiple factors present in patients with progressive renal disease, including hypertension, hyprelipidemia, hyperhomocysteinemia, diabetes mellitus, and hyperparathyroidism. Experimental studies have provided in vivo and in vitro data to support the notion that lipid abnormalities contribute to glomerular and interstitial injury of the renal parenchyma. Hypercholesterolemia and increased low-density lipoprotein (LDL) cholesterol are prevalent in patients with the nephrotic syndrome. Plasma high-density lipoprotein (HDL) cholesterol is decreased, and reverse cholesterol transport is impaired in hemodialysis (HD) and pre-ESRD patients. Chronic renal failure patients treated with HD have an increased prevalence of intermediate-density lipoprotein (IDL), and lipoprotein(a). The findings in the diabetic patients corresponded to those in non-diabetic patients with renal failure, but diabetic patients have higher apolipoprotein C-III and apolipoprotein E concentrations. Impaired lipid metabolism is common in patients receiving peritoneal dialysis (PD). In the most of the ESRD patients treated with peritoneal dialysis hypercholesterolemia and hypertriglyceridemia are found. Wide panels of therapeutic interventions aimed at correcting the lipid abnormalities that may develop in chronic renal patients, as well as in ESRD patients are currently available. Although some novel pharmacological agents are remarkably effective for returning the lipid abnormalities to normal, there is still no convincing evidence based on long-term prospective studies which clearly demonstrate a significant reduction in cardiovascular morbidity and mortality of ESRD patients. The therapeutic approaches, which may be considered, include mainly dietary and life-style modifications, selective use of some technical components of dialysis systems, and the judicious prescriptions of lipid-lowering drugs.

Humans↗
PubMedDate not supplied

[Recirculation of urea and dialysis efficiency using dual-lumen dialysis catheters in various locations: may the venous lumen of the catheter be used as the arterial lumen and vice versa?].

AIM: To measure percentage of urea recirculation in hemodialysis by a dual-lumen central venous catheters of various localisations (e.g. jugular, subclavian and femoral), and also in cases when the venous lumen of the catheter is used as arterial lumen, and vice versa, and under these conditions to evaluate the efficiency of hemodialysis based on the measurements of urea reduction ratio. METHODS: Percentage of urea recirculation was measured in the patients with acute and chronic renal failure who underwent hemodialysis by a temporary dual-lumen central venous catheter of different localisations (jugular n = 16, subclavian n = 20, femoral n = 20). The measurements were done in cases when arterial line was connected to arterial lumen of the catheter, and venous line to the venous lumen of the catheter (correct connection = RI), and vice versa, i.e., when arterial line was connected to venous lumen of the catheter, and venous line was connected to arterial lumen of the catheter (reversed connection = R2). The efficiency of hemodialysis was evaluated by measuring urea reduction ratio in cases with the reversed (R2) connection. RESULTS: Statistically significant differences were found between R1 and R2 for jugular catheters (R1 = 2.38 +/- 1.09%, R2 = 7.59 +/- 1.42%, n = 16, p = 0), for subclavian catheters (R1 = 3.03 +/- 3.15%, R2 = 15.8 +/- 7.18, n = 20, p = 0), and for femoral catheters (R1 = 9 +/- 6.56%, R2 = 29.2 +/- 11.8%, n = 20, p = 0). Statistically significant differences were also found between R1 of jugular catheters and R1 of subclavian catheters (2.38 +/- 1.09%, n = 16 and 3.03 +/- 3.15%, n = 20, p = 0.0001), further on between R1 of jugular and R1 of femoral catheters (2.38 +/- 1.09%, n = 16 and 9 +/- 6.56%, n = 20, p = 0), as well as between R1 of subclavian and R1 of femoral catheters (2.38 +/- 1.09%, n = 20 and 9 +/- 6.56%, n = 20, p = 0.0001). Also statistically significant differences were found between R2 of jugular and subclavian catheters (7.59 +/- 1.42%, n = 16 and 15.8 +/- 7.18%, n = 20, p = 0.0003), between R2 of jugular and femoral catheters (7.59 +/- 1.42%, n = 16 and 29.2 +/- 11.8%, n = 20, p = 0.0007), and between R2 of subclavian and R2 of femoral catheters (15.8 +/- 7.18%, n = 20 and 29.2 +/- 11.8%, n = 20, p = 0.0029). The measurements of urea reduction ratio that we have done for some of the catheters under R2 conditions showed a statistically significant difference between femoral and subclavian catheters (51.45 +/- 5.62%, n = 20 and 63.75 +/- 7.61, n = 20, p = 0), and between femoral and jugular catheters (51.45 +/- 5.62%, n = 20 and 64.3 +/- 5.23%, n = 16, p = 0). No statistical differences were found in urea reduction ratio between jugular and subclavian catheters (64.3 +/- 5.23, n = 16 and 63.75 +/- 7.61%, n = 20, p = 0.8). CONCLUSION: When hemodialysis is delivered by a correct blood lines connection the measurements have shown a decrease in urea recirculation by 5% for jugular and subclavian catheters, and 5%-10% for femoral catheters. However, in cases when the venous lumen of the catheter is used as an arterial lumen, and vice versa, urea recirculation is below 10% for jugular catheters; whereas in femoral catheters the percentage is higher than 20%. Despite so high percentage of urea recirculation, that we obtained for such use of the catheters, urea reduction ratio in hemodialysis via jugular and subclavian catheters is > 60%, whereas via femoral catheters, the percentage is significantly lower. Consequently, the efficiency of hemodialysis is reduced, and such use of femoral catheters should therefore be avoided.

Catheterization↗